DOCUMENT RESUME

ED 028 091By Haber-Schaim. UriIntroductory Physical Science; Physical Science II: A Progress Report.

Education Development Center, Newton, Mass. Introductory Physical Science Group.

Pub Date 68Note- 34p.EDRS Price MF-S0.25 HC-SI.80Descriptors-Achievement Tests, *Curriculum Development. Evaluation. Leadership Training, Objectives,

*Physical Science& *Science Course Improvement Project, *Secondary School Science, Student Attitudes

Identifiers-Introductory Physical Science

This report contains articles on the preparation of Introductory Physical Science

(IPS) for commercial publication, objectives and content of the course, and the IPS

leadership, training program. Two articles discuss testing as a means of studeni

evaluation, and statistics are presented to indicate student performance on IPS by

grade level and scholastic ability. A series of short articles concerning IPS

apparatus, the IPS paperback edition, and the IPS philosophy is presented. Two

articles concern the development of Physical Science II. One is entitled, "The What and

Why of Physical Science II." and includes the table of contents of the new course. The

other article is entitled, "College Admissions and Physical Science II." Lists of colleges

which will accept Physical Science II and IPS for admission credit are presented. An

article concerning student attitudes toward Physical Science II and one concerning

teacher attitudes complete the report. (BC)

SE 006 400

'.DEvELOPMENT CENTER

U.S. DEPARTMENT OF HEALTH, EDUCATION & WELFARE

OFFICE OF EDUCATION

THIS DOCUMENT HAS BEEN REPRODUCED EXACTLY AS RECEIVED FROM THE

PERSON OR ORGANIZATION ORIGINATING IT. POINTS OF VIEW OR OPINIONS

STATED DO NOT NECESSARILY REPRESENT OFFICIAL OFFICE OF EDUCATION

POSITION OR POLICY.

A Pito Repo/I

For further information on Introductory Physkal Science

or Physkal Science II, write to

IPS Group

Education Development Center

55 Chapel Street, Newton, Massachusetts 02 I 60

Cover Design by R. Paul LarkinPhotographs by Victor E. StokesProduction by Benjamin T. Richards

INTRODUCTORY PHYSICAL SCIENCE

Accent on ImplementationBy URI HABER-SCHAIMDirector, IPS Group

The preparation of materials for the first com-mercial edition of IPS is now almost completed.

Student text, Teacher's Guide, laboratory equip-ment, and one set of achievement tests are nowavailable. Two additional sets of multiple-choiceachievement tests and a booklet on laboratory

tests will be published soon. The use of the coursein the schools is rising rapidly and brings with itthe problems of large-scale adoptions. It alsofocuses attention on remaining weak spots in

science programs in secondary schools. It is notsurprising, therefore, that the efforts of the IPSGroup are now directed to assisting schools in thesuccessful implementation of the IPS program and

to creating a second-year course in physical sci-ence to follow it. This progress report deals withthese two aspects of the Group's work.

From the beginning of the IPS program we have

urged schools to try the course only with a teacher

who has had the opportunity to study it in sufficient

depth to understand its philosophy and to acquire

the basic skills for teaching it. Several ways wereavailable to teachers to get the necessary training.

First of all, there were a number of summer in-

stitutes supported by the National Science Founda-

tion. These were followed by NSF-supported in-service institutes and Cooperative College School

Science programs and workshops supported andorganized by state departments of education.

Further opportunities for obtaining the neededtraining were later provided by local workshops

directed by selected IPS teachers. The expensesof these workshops were met in some cases by the

school systems themselves, and in others by thepublisher of the IPS materials.

All these sources however, were not sufficient to

meet the demand for trained IPS teachers. Anew way had to be found to supply the trainingwhere it was most needed. An attempt in thisdirection was made last summer through the Lead-ership Conference. This is described in the article

by Gerald Abegg.

1

One of the most noticeable discrepancies be-

tween what is being preached and what is beingpracticed in schools is in the field of testing. Allscience teachers agree that it is important to teach

the students to think, to understand the basic prin-ciples of science, to apply their knowledge to new

situations, etc. However, to produce tests which

will be consistent with these aims is not a simplematter, and students very quickly discover whatreally counts when it comes to getting a good mark

for their work. It was therefore imperative to pro-

vide juidance for the teachers to judge achieve-

ment in the IPS program. In this course the stu-dent engages in a large variety of activities which

range from manual operations like assemblingequipment, taking measurements, and plottinggraphs to analyzing results, drawing conclusions,and solving problems. No single test can measureachievement in all these activities, and a teacher

must use several yardsticks to justify his evalua-tion of a student's progress. A review of the IPSGroup's work in these matters is given in the arti-cles of John Dodge and Raymond Thompson.

Experimentation by the students plays a key

role in the IPS course. This can give satisfaction

or frustration, depending on the quality of theequipment used. Normally there is no stage inthe release of apparatus which is equivalent to theproofreading of a book. Therefore we had tolook for new ways of guaranteeing that the equip-

ment which reaches the schools is up to standards,while at the same time encouraging competition

among manufacturers and utilizing their know-how in production and manufacturing. How we

do this is described by James Walter.One of the things I always found most bewilder-

ing is the common practice of schools providingbooks for the students for the duration of theschool year only. From the junior high school up

it seems reasonable that a book not worth keepingis not worth studying in the first place. To en-courage school systems to let their students keep

2the IPS textbook the publisher was asked to makeit available both in hardcover and in paperbackformat. Comments on how the paperback is be-

ing used are given by Edward A. Johnson, RobertT. Fitzgibbon, Arthur G. Suhr, and John N.Meade.

Objectives and Contentof the Course*

By URI HABER-SCHAIM

There has been considerable progress in recentyears in the teaching of physics, chemistry, andbiology in the secondary schools. Th Pe PhysicalScience Study Committee course in physics, theChemical Bond Approach and Chemical Educa-tion Material Study in chemistry, and the Biologi-cal Sciences Curriculum Study in biology are wellknown. But these courses do not exhaust thefield of science instruction at the pre-universitylevel. Some science is usually taught in grades 7,8, and 9 in the junior high school, often in allthree grades. By providing new course materialfor the last three years of high school, we in-creased the contrast between those years andgrades 7, 8, and 9.

The question is: What can one do, or whatshould one do, to extend the gains achieved inthe upper grades to the lower ones? What shouldbe the content, what should be the emphasis, andwhat, primarily, should be the purpose of scienceinstruction in those years? There are certainlymore than one answer to these questions. Herewe have confined our attention to a one-yearcourse in physical science, aimed primarily at theninth grade.

It is worth while to recall briefly the mainquestions which we asked at the very beginningof the PSSC physics course development. We

asked: What is the objective of the course?What do we want to achieve? What is the pur-pose? What are the values we want to get across?From the answers to these questions we con-

*Adapted from lecture given at FloridaState University, Ta Ilahauee. Reprinted byrequest from an arlier progrus report.

structed an outline of what the content should beand how it should be taught. The chemists andbiologists did likewise in planning their programs.In planning the present course for junior highschool we had before us the work of PSSC inphysics, of BSCS in biology, and of CBA andCHEMS in chemistry, so the matter of aims wasnot an entirely independent question any more.

The greatest handicap faced by science teachersin the new curricula is that most students in seniorhigh school have no experience in observations,no basic laboratory skills, no knowledge of howto apply elementary mathematics to experimentalresults; they also lack the ability to correlate anabstract idea with a concrete situation. Oftenthey have no idea of orders of magnitude, nofeeling for approximation, no ability to judgewhat is important and what is not.

Often their earlier training has given studentsthe idea that science is remote from real life andfrom anything they can do. The standard phrasein many textbooks is that "scientists have foundsuch and such," and "scientists do so and so," andthe student is requested just to memorize it. Sci-

ence in many books means primarily vocabulary.All too often, important words are printed inheavy type and the student is asked to rememberthem. In science, however, words can have mean-ing only as they are associated with an action oran operation.

Students need time to digest knowledge. Fromthe very first, PSSC physics teachers kept sayingthat if only we could get into the earlier gradessome of the basic ideas and skills which areneeded so badly in PSSC, it would make the

course much easier to teach and give the studentsmuch more time to digest the materials. And so,out of requests from teachers in the field camethe call to start something to serve as a commonfoundation for the later courses in the senior highschools. This means not only a foundation of sub-ject matter, but also an attitude of inquiry coupledwith experimental and mathematical skills.

Physics and chemistry are elective subjects, anda fair fraction of the school population takes tenthgrade biology as its last course in science; somestudents have no science at all in senior highschool. Unfortunately, many can even get throughcollege with no additional science, and will be illequipped to understand a world dominated bythe terminology and implications of science andtechnology. Therefore, our new course must alsoserve as a terminal course in physical science formany students, as well as provide a foundationfor further work.

Thus we must have a program to serve twopurposes: on the one hand to be a sound founda-tion for future physics, chemistry, and perhapsbiology courses; and on the other hand to furnishsufficient nourishment in the essence, the spirit,and the substance of physical science to be agood terminal course for those who will not studyphysical science later on.

We believe that there are certain values andskills that can and should be taught in junior highschool science. First, we want to give a feelingfor the kind of human effort that is involved inthe development of science. We want to putacross the point that the root of all science isphenomena and that the names come later. Weshould like the student to get his informationfrom the original source, from nature itself. Thiscalls for real investigation in the laboratory. Butscience is not all laboratory work. We have tocorrelate and generalize our observations. We

have to construct models or theories which canbe manipulated logically and which will raisenew questions. Later we do other experiments toseek the answers to these questions.

This poses many technical problems in con-structing such a course. It is hard to design anexperiment which, when handled by ten youngfingers, will come out the way you think it should.Following a schematic drawing in a textbook isnot enough.

3

Time is always an important limiting factor inthe laboratory, and this may make it hard to drawvalid conclusions from the limited data available.This difficulty can often be relieved by combiningthe data of all the students and putting it on theboard. Here is a good opportunity to teach thehandling of errors. When students compare theirmeasurements, they see the errors and learn howto decide which results are significantly differentand which are within the experimental errors.We can save time by not asking all students todo exactly the same experiment. For example,in connection with the idea of boiling point, allthe students boil water, but each uses a differentquantity and some unknowingly get water withvarious amounts of salt dissolved in it. Eachstudent gets a different graph of temperatureversus time, and all of these are placed on theboard. We thus have enough information to dis-cuss whether the boiling point depends on thequantity of water or whether there are other sig-nificant differences.

CONTENT OF THE COURSE

In selecting the topics, we used the same cri-teria as we did in the construction of the PSSC.That is, we asked: How much does the studentbenefit by learning this? How useful is it laterin the development of the story? We feel that atopic that appears in our outline only once shouldnot appear at all; it has no "mileage," and we cando very well without it.

No particular set of prerequisites was assumedin the students except some general familiaritywith our technological society. In other words,we assumed that the students had seen commonhousehold instruments and objects. For example,we assumed they would know what a thermom-eter is, but there is a great difference betweenthat and assuming that they had heard aboutatoms. The student can hold the thermometerin his hand and see the liquid rise when he putshis thumb on the bulb. The atom is anotherstory; he has never seen one, and we must notrely on things with which he has no associationor experience.

We have chosen as a central theme of thiscourse the introductory study of matter. If welook around us we see a bewildering variety ofmatter; we can try to bring order into this seem-

4

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The equal-arm balance designed for the IPS laboratory. Note the box containingbead weights in various amounts.

ing chaos by breaking up the many kinds of matterinto simpler components, and then combiningthese components into a pattern. If we cannotbuild a pattern, then we can only catalogue things

as a collector catalogues stamps.

Characteristic PropertiesScientific inquiry begins when we do things on

purpose instead of just compiling our experienceas it comes. When we look outdoors, we seedifferent kinds of leaves of different colors anddifferent sizes; we see stones; we see trees. We

know that these things are different, because wehave touched them many times, held them in ourhands, broken them. This is all fine, but then wemeet up with two things which on first sight lookthe same. We ask: Are these two objects thesame, or are they not? Then we have to do thingsto them deliberately in order to find out. To theperson working in the field, it is obvious that youdo the same thing to both, and you see whether

they react the same. Yet, strangely enough, thisbasic concept the idea of doing the same thingto two samples to see if they react the same way

is completely missing from most texts.Perhaps even more fundamental than the idea

oi differences between substances is the idea ofquantity. It is essential to be able to say "howmuch"swithout regard to what particular thing we

have. How can we compare an amount of chalkwith an amount of paper, and an amount of gasor air with an amount of water? The answerlies in the balance: we say that two amounts ofmatter are the same when they are in equilibriumon the equal-arm balance. We call this property"mass," without elaborating further. The nextstep is to look for properties which are independ-ent of the amount and the shape and other con-ditions. We must show first that there are indeedsuch characteristic properties that do specify asubstance as distinguished from other substances.

There is a large variety of characteristic proper-ties to choose from, and we cannot discuss all ofthem; we choose those which can be used toseparate substances from one another. Densityis one: some things will float in water; otherswill sink. Solubility is another: some things willdissolve readily; others will not. Boiling point isanother: one can separate substances by fractionaldistillation.

There is another consideration which influencesthe choice of characteristic properties; this is theirusefulness in building a model or theory of matter.We need properties which can be combined togive us a unified picture of matter. In this con-text the similarity in the behavior of gases and thediversity in the behavior of liquids and solidsis very significant.

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Apparatus for collecting gas from thesetup is a sheet of peg board supportedparatus are held by clips bolted to thecompact arrangement which can be used

for much specialized hardware.

Mixtures, Pure Substances, and Elements

The course proceeds to the separation of mix-

tures. We use all these characteristic properties

to break up what we find in front of us into asmany components as we can. We use the avail-

able tools quite indiscriminately, and we remind

our students that men used these tools king beforethey knew there were such things as physics and

chemistry. For example, people knew about grain

alcohol for several thousand years and used it as

a solvent, without any chemical theory. We also

are going to use it as a solvent, without asking

what happens or why. The fact is that if I putone substance into alcohol, it dissolves; some other

substance does not. Here I have a way of sepa-

rating substances.From the separation of mixtures we get the

idea of a pure substance; we define it by certain

rules of the game. We start with something; we

heat it and freeze it and dissolve it and filter it.We keep ,doing all kinds of things to it, and wekeep getting back the same substance; the material

does not separate into two components which re-

act differently. We say that this is a pure sub-

stance. With these rules we define pure substances

distillation of wood. The basic laboratoryby a heavy base; the smaller pieces of ap-

peg board. This makes an inexpensive and

on an ordinary desk and eliminates the need

and we see that, unlike the mixtures, they have

definite characteristic properties.Here the rules of the game are applied in prac-

tice and in our text: YOU get something. You

try to break it up into components by whatever

techniques you have developed. (Other tech-niques, which are beyond the reach of the studentlaboratory, are described in the textbook.) Then

you measure the characteristic properties of yoursample of matter and you check them against a

table of data. If there is such a combination of

properties tabulated, it has a name, and you say,

"Aha, I have so-and-so." And if it does not have

a name, you may call it whatever you wish.Now we add to our arsenal. Instead of just

distilling and freezing and crystallizing and so on,

we permit a wider range of tools, such as heatingwith charcoal and boiling in hydrochloric acid to

break up those few substances which would notbreak up under the previous treatment. This is

how we get to the idea of elements, by way of an

operational definition. Elements are those things

that do not break up into simpler components,

even when they are put in acids or heated or sub-

jected to electric currents, or treated in certain

other ways.

6

.'

An experiment to demonstrate radioactivity, as astep toward the atomic model of matter. Samplesof six different substances in small plastic boxes areplaced on a photographic film enclosed in blackpaper. After three days some parts of the filmare found to show effects like that in the photographat the right.

Radioactivity

Ultimately, we want to get an atomic pictureof matter. But if we are really honest and donot just rely on our beliefs, we find very little tosuggest atoms in anything which we have de-scribed here. When you pour water, it lookscontinuous; if you look at crystals of salt, thecrystals are big; they dissolve, and there are nomore crystals, and the resulting liquid looks con-tinuous. We need something to give us somehint, some real indication that there is a dis-creteness in all matter.

We have chosen a path through radioactivity tothe atomic picture, because radioactivity is onearea where discreteness is very much in the fore-ground. Anybody who has ever heard a Geigercounter click knows what I mean by discreteness.Discreteness is apparent in the grains of a photo-graphic film exposed to radioactivity. Eventhough the intensity of the radiation may vary,

the grains are always the same size (with thesame kind of film). The tracks in a cloud cham-ber also give a strong impression of discreteness.

Now you may say this is just ra6oactivity, aspecial phenomenon; where does mauer come in?Matter comes in because, after many clicks, youfind that you have collected a quantity of a newelement.

Previousiy, the word "atom" has nowhere ap-peared, but now we offer the suggestion that allmatter may be made up of particles. We saythat we can count individual particles, and if wecount long enough we can see a measureableamount of gas. Incidentally, we plan to do thisexperiment by brute force on film, using a large

7

Apparatus for measuring the thermal expansion of a long tube. Steam from boilingwater in the test tube passes through the length of the tube, heating it and causingit to expand. The left-hand end of the tube is held firmly by a clothespin, preventing thisend of the long tube from moving. The right-hand end of the tube is free to move,and its expansion is amplified end measured by the rotation of the circular scale.

amount of radioactivity, 20 curies. You willsee the spectra of the resulting gas and see thatit is helium.

The Atomic ModelNow we come to the second part of the course,

where we theorize and make a model. We re-examine what we have done before, but now webegin to do some abstraction. We start slowly,building up as we go which is the way thatscience works, in fact. The first idea we proposeis that there are particles; these are probablyvery small, because we never notice them in dailylife. The minute we make such a statement tothe youngsters. we have accepted an obligationto say how many and how small; otherwise it isa meaningless statement.

We say that the atoms are very small thingswhich are different for each element, and thatin chemical combination they are grouped togetherin molecules. This very simple picture alreadycorrelates a great deal of information which wehave gathered in this course. It explains howwe can get an element back out of a chemicalcombination; all chemical reactions are, in thislanguage, a regrouping of existing things. It makessense that the total mass remains constant in re-actions if we believe that atoms only changepositions or change their combinations. Each

pure substance, each compound, always has thesame composition because we always take somany of one kind of atom and combine it withso many of another kind.

So far we have used only the discreteness, butnow we can see also that there are more propertiesthan that. We recall that there are some solidswhich have high density and are very hard tocompress. Apparently these atoms act like hardobjects touching each other. Gases are very easyto compress and have a low density. Apparentlythese atoms are far apart, so the low density andthe compressibility also fall in line and make asensible pattern. With oleic acid we can find thethickness of a monolayer and thus get the size andmass of a molecule. So far, our atoms are stadc;they have a certain size and are a certain distanceapart.

The Kinetic Picture of HeatNow we come to the next phase, where we let

the atoms move. Everybody knows that if youopen a bottle of gas, the gas will come out; thisleads to the idea of molecular motion, and to themolecular picture of heat. We have been usingheat all along, but now we want to relate thethermal properties to the atomic picture just aswe did the chemical properties. We start the dis-cussion of heat and the gas model of heat without

8

any detailed laws of mechanics, but we make useof analogy. We theorize a molecular picture of

two very basic concepts in physics, the tempera-ture and the quantity of heat (which are confused

no end by students). We move from the gas intothe solid and get the idea that hot moleculesand atoms move faster than cold. We say thatif things collide, the fast ones slow down and theslow ones speed up; that if you heat somethingit becomes warmer, because you make its mole-cules move faster; and so on. This brings us tothe ideas of thermal energy.

In the final chapter, thermal energy is measured

in calories by its heating effect on water. Specific

heats are determined, and then heats of reaction,solution, fusion, and vaporization are studied.These latent forms of heat, not associated withmolecular motion, are related to the rearrange-ments of atoms in chemical reactions, solution,and changes of state.

In summary, we believe that this course will

greatly facilitate the teaching of physics and

chemistry: several chapters of chemistry can be

eliminated and much of the first part of PSSC

will not be needed. But, most important, webelieve that pupils will enter physics and chemistry

with an improved orientation and attitude toward

science, and well-equipped with essential skills.

r

The stretch of a wire when it is pulled can also be measured by an amplifier. The wire

is fastened to a small metal drum that rotates as the wire stretches. Attached to the

drum is a long pointer, which amplifies the stretch of the wire.

IPS Leadership Training ProgramBy GERALD ABEGGIPS Group, on Leave from Kansas State Teachers College

Emporia, Kansas

Widespread acceptance of the IntroductoryPhysical Science Program has resulted in a severeshortage of qualified teachers to implement theProgram. Summer and in-service institutes, spon-sored by the National Science Foundation, havecontributed significantly to the pool of trained IPSteachers, but the supply falls far short of the de-mand. In addition, several areas of the country

:o p

Gerald Abegg at the Leadership Conference map.

which have not made much effort in IPS teachertraining are making large-scale adoptions of IPS.When school administrators in these areas soughtto solve their IPS teacher-training problem withlocal or regional workshops, they found that IPSworkshop teachers were extremely scarce or non-existent.

In an effort to increase the quantity and qualityof IPS teachers, the IPS group obtained a grantfrom the National Science Foundation to supporta leadership program. This program is designedto locate qualified science teachers and to preparethem to instruct other teachers in the use of IPS.

Late in the spring of 1968, information noticeson the leadership program were distributed toschool districts which had reported a need for

9

trained IPS teachers. In addition, the publisherof the IPS textbook distributed notices and appli-cation forms to teachers in schools making IPSadoption for the 68-69 school year. Potentialparticipants in the program submitted applicationsin which they indicated their teaching ewerience,commitments to teach IPS in the ensuing schoolyear, plans for a local IPS workshop for otherteachers, and ability to participate in the totalprogram. In each case, the participant's schooldistrict was requested to present a letter indicatinga willingness to support the individual in the or-ganization of the local workshop.

After 114 applications had been reviewed,eighty-seven teachers were selected to participatein a summer Leadership Conference held at theColorado School of Mines in Golden. The partici-pants received no stipend for the 21/2-week con-ference, but were provided round-trip transporta-tion from their respective home towns, room andboard, and miscellaneous expenses. Seventy-eightteachers accepted the invitation to participate inthe conference and arrived in Golden on June 16to begin the intensive training program.

The Leadership Conference was designed to pre-pare the participant to teach IPS in his own class-room and to conduct a local workshop for hispeers who are also teaching IPS. Sktce nineteenof the conterence participants had some experiencein the teaching of IPS, they were assigned to aspecial work group with the task of studying someof the IPS experiments in depth, as well as provid-ing a source of personal experiences which wereshared with the remaining participants. The latterwere divided into four small discussion groups tofacilitate concentrated study of the full IPS pro-gram. The staff at the conference rotated amongthe five groups in an effort to keep the variousworking sessions fresh and to permit the maximuminterchange of ie.eas between staff and participants.Film showings, testing, and major presentationswere held in a lecture hall, with all other work

10

divided between classrooms and the laboratories.During the late afternoon and evening hours,

small group conferences were scheduled to com-plete the details of the local workshops which theparticipants were to conduct. The schedule forthese local workshops was set at five full days'instruction prior to the opening of school, and tenfull days during this academic year. In a few casesit was necessary to devise a plan involving 15 or20 partial day sessions, but in all cases the localworkshop was designed to meet for a minimum of100 hours of instruction.

Personnel from the IPS staff are scheduled tovisit each of the local workshops during the in-service phase to aid in resolving implementationproblems and to evaluate the overall effectivenessof the workshop program. At the conclusion ofthe local workshop, each participant who is con-currently teaching IPS will be issued a certificateindicating his or her participation and successfulcompletion of the program. In the large majorityof school districts, this certificate will be recog -

nized as professional credit earned by the teacher.A special grant by the publisher will pay one-

half of the workshop instructor's salary, with thedistrict or districts sharing the costs of the addi-tional salary and expendable supplies used in theworkshop.

The Program at WorkApproximately 50 workshops met for the five-

day pre-school session in August and are now in-volved in the in-service phase. As a result ofsevere financial problems and local organizationaldifficulties, it was necessary to delay the remainingworkshops until the summer of 1969. These work-shops will thus coincide with the full-scale imple-mentation of IPS in the regions they serve.

In October and November, each of the Leader-ship Conference participants attended one of sevenregional three-day meetings. These follow-up ses-sions provided an opportunity for each of the par-ticipants to discuss his or her local workshop withthe IPS staff and other participants. Many prob-lems were identified and solved in these discussions.

The feedback from these meetings indicated thatthe summer training session was quite effectivein preparing the participants for their respectiveworkshop assignments. Naturally, some leadersare more successful than others in relating to their

peers and in taking full charge of the situation.In the final analysis, the most critical problem

has been created by local school officials who arereluctant to support the workshop effort. Someschool officials have attempted to reduce the work-shop to a series of informal chats, while othershave insisted that the workshop instructor couldnot be paid from local funds. In addition, morethan half of the workshops are conducted on theteachers' time on Saturdays and evenings.

In situations where the district awards salarycredit for the successful completion of the work-shop, the teachers are pleased with the arrange-ments; however, teachers aye quite unhappy in thefew situations in which neither credit nor releasedtime for workshop attendance is provided. Theproblems created by these undesirable situationshave resulted in a very poor attitude in all in-volved. The workshop leaders indicate that thefive-day preschool meeting is the most valuablepart of the workshop plan. They agree that thisis largely due to the feeling of fellowship developedin the day-long sessions as well as the anticipationof school opening. The in-service phase of theworkshops is constantly plagued with interferingand conflicting activities; the workshops that suf-fer from lack of administrative support seem to bemost affected by these scheduling and attendanceproblems.

Although the number of teachers involved is notas large as anticipated, more than 350 teachersfrom 21 states are participating in the local work-shops. In addition many school districts which forany of several reasons were not able to organizea workshop this year, have already scheduled a15-day session for next year.

While the problems of communication and co-ordination seem insurmountable, the interest andcooperation generated among the teachers andadministrators at the local level appear to be oneof the strengths of the program. In a large num-ber of situations, the IPS local workshop is thefirst attempt at training teachers through theirpeers and within their own environment. Severalcolleges have made arrangements to provide facil-ities and credit for the local IPS workshops. Thewillingness and ability of the local schools to adaptthe IPS Leadership Training Program to their re-spective situations is the key to the success of theentire program.

11

TESTING

Measuring Student AchievementBy .;OHN H. DODGEIPS Group

The purpose of the IPS course is to give all stu-dents a beginning knowledge of physical scienceand to offer some insight into the means by whichscientific, knowledge is acquired; the method em-ployed to achieve these goals is one of studentexperimentation and guided reasoning on theresults of such experimentation. In measuringachievement in the IPS, one would like as far aspossible to evaluate progress of students in termsof these goals.

No method of measuring achievement can beentirely satisfactory. Some sort of selection ofitems to be tested is necessary, and one can onlyhope that the selection made is representative ofthe whole of the students' knowledge and under-standing. Nor is it easy to be certain that a stu-dent's response to a test item is dictated solely bythe instruction he has received; his behavior is theresult of the influences of all factors that have beenbrought to bear on him, not necessarily limited tothose encountered in a particular class. And thereis no guarantee that any particular test item is infact a valid measure of the desired attitude orunderstanding.

It seems well, therefore, that a teacher shouldestimate student achievement in a variety of ways,rather than limit himself to a single techniqueapplied at wide intervals.

Here are some of the things a teacher can do toappraise a student's progress:

Observe and make a few simple notes onthe student's performance in the laboratory.

Make some notation regarding the stu-dent's participation in class discussions.

Inspect the solutions to the assigned prob-lems in the Home, Desk, and Lab section atthe end of each chapter.

Inspect from time to time the laboratorynotebooks for completeness, accuracy, read-ability, and clarity.

Give short quizzes (five minutes or so) onan advance reading assignment or on mate-rial just completed.

Give laboratory tests.Give the chapter quizzes suggested in the

Teacher's Guide.Give the IPS Achievement Tests.

Generally, the more notations a teacher makesin his record book about each student, the easierit is to explain a report-card mark to parents,counselors, and administrators. Many of these no-tations can be made without grave interruption toclass progress. For example, during student workin the laboratory the teacher can keep his eye onwhat is going on, and at the same time checknotebooks and other written work.

Students learn to adjust rapidly to what ateacher requires. If the teacher never pays morethan superficial attention to laboratory reports orother written work, concentrating only on generalappearance and neatness, the students will supplyhim with clean and neat nonsense. On the otherhand, it is usually impossible to perform the im-mense labor of scrutinizing with care every wordthat comes in. A wise teacher will select fromtime to time representative laboratory reports orsolutions to Home, Desk, and Lab problems andwill examine them carefully, assigning them gradesrepresentative of the knowledge and understandingof science the papers actually show. Certainly nograde should be entered for a student in theteacher's record book unless it represents a de-fensible estimate of the student's attainment of thegoals of the course. It is far better to enter a rela-tively small number of meaningful grades in therecord book than many that do not represent validestimates of the student's progress.

The time devoted to formal testing should notbe excessive. It is recommended that 'the Achieve-ment Tests be used as appropriate; if the giving of

12

one of these tests is not practical during the periodcovered by a report card, one or more of the chap-ter quizzes in the Teacher's Guide might be usedinstead, the teacher choosing the number and com-bination of questions from the quizzes that is ap-propriate to the time available. In a report-cardperiod of thirty school days, two days are proba-bly sufficient for formal testing.

Chapter QuizzesBound in the IPS Teacher's Guide is a series of

quizzes, one for each chapter except the first. Mostof the questions are objective, requiring the studentto select one of five possible answers to the ques-tion posed. However, other types of questions areincluded as well: those that require a student toread and interpret a graph, make and exhibit cal-culations, or write an explanation in a paragraphof a few carefully constructed sentences. As sug-gested above, the teacher may use the quizzes inwhole, in part, or in any desired combination; heis free to reproduce them in quantity for his classes.

These quizzes have been so constructed that thedistribution of correct responses will resemble thatof the Achievement Tests, although the quizzes

have not been given a formal analysis. They wereused by pilot teachers, whose comments and sug-gestions are incorporated in the present edition.

Achievement TestsQuestions for Achievement Tests are prepared

in the same spirit that governs the preparation of

Home, Desk, and Lab problems. Little use ismade of questions designed only to test a student'smemory; usually, situations are presented in whichthere is some element slightly different from thosethe student has specifically worked with in thelaboratory or in the textbook. Hence, some judg-ment is usually required of the student, based onhis understanding of principies and procedures.

The questions selected are of the type that pre-sent a situation and offer five possible responses toit, of which the student must pick the single correctone. An attempt is made to provide incorrect re-sponses that correspond to errors students arelikely to make when their knowledge and under-standing are inadequate, so that student responsesmay indicate where instruction should be im-proved; however, we have not succeeded in doingthis in all cases.

As an example, consider the question repro-duced on the opposite page.

The question is based on an important experi-

ment performed in Chapter 3 on CharacteristicProperties, and on the discussion that follows it.

In this experiment the student heats a test tubecontaining either paradichlorobenzene or naphtha-

lene in a water bath until the solid is melted andraised to a temperature of about 90°C; then thesubstances are allowed to cooi, the student record-ing the temperature of the water and that of thesubstance in the test tube until the substance hascompletely resolidified. The student then preparesa graph of his data, and in a class discussion thegraphs of all the students are examined and com-

pared.From this experiment, the student learns that the

cooling of a liquid that does not freeze in this tem-

perature range exhibits a regular, smooth tempera-

ture change. However, when the liquid freezes, the

temperature remains stationary during the change,

at a point which depends on the particular sub-stance but is independent of its quantity, providedthat the substance is not mixed with another.

The question presents a situation similar to thatof the experiment the student has performed. Thegraph presented as a part of the question indicates

that the substance is a single substance with afreezing point of about 45°C, as indicated by thehorizontal section of the cooling curves. The stu-dent is expected to understand that using the larger

quantity of the substance would not affect the ex-istence of the horizontal section of the graph northe temperature at which it occurs; but that if theapparatus and procedure were the same, it wouldprobably take longer to cool and to Treeze. Hence

the correct response is (C).Responses (A ) and (B) would probably be

selected by students who have not learned that thefreezing point is characteristic of the substance and

not of the quantity of it, but think that doublingthe mass would change the freezing point. Sincethe new quantity of substance is double the orig-inal amount, these wrong choices give the studentthe choice of a centigrade temperature double theoriginal freezing point or one-half of it, dependingon which way he thinks the quantity of substancechanges its freezing point.

Response (D) gives the careless student achance to confuse the substance undergoing solidi-

%

4. 10 grams of a substance is heated until it melts,

then it is allowed to cool in a freezer whose tem-perature is 0° C. While it is cooling, the tempera-

ture is recorded each half minute and the graph

at the right is plotted from the data obtained.

Had 20 grams of the substance been heated and

cooled, which graph below would best represent

the temperature of the substance as a function

of the time?

(A)

go

so

20

o

so

(C)

20

00 5 10 15 20 25

TIME (min)

-11

0 5 10 15 20 25

TIME Inn/

4... OM

20

00 5 10 15 20 25

TIME (monI

-

(D)

100

10

60

40

20

0o

100

10

60

40

20

00 5 10 15 20 25

TIME (moni

,

-

.41. ..

, ..

5 10 15 20 25

TIME (mm)

,

AS

100

at. solaix= 60o-

(E) <ccti 402'a)-

20

0o

_

-5 10 15 20 25

TIME (nn)

fication with one that does not. The graph offeredhere resembles the one he prepared in the experi-

ment performed with water.Response (E) gives the careless student a

chance to confuse the solidification of a singlesubstance with that of a mixture of substances. Ilehas not studied the cooling of mixtures in thelaboratory, but this is a part of the discussion fol-

13

lowing the experiment, and a cooling curve of a

mixture of substances candle wax is printed

in the text.The selection of the correct response shows that

the student understands the particular point; if he

selects other responses, there is some indication of

the nature of his misconception and o hint as towhat might be done to straighten him out.

14

All of the Achievement Tests have been triedout in selected pilot schools, with enough studentstaking the tests so that meaningful statistical anal-

yses could be made by the Educational TestingService. On the basis of these analyses, faultyquestions were eliminated, revised, or replaced.

he published tests are therefore likely to be moresatisfactory than the objective tests a particularteacher makes up for his own classes; moreover,the teacher who uses them has the means of com-

paring the performance of his students with that of

the pilot group of students.In order to relate the statistics obtained from the

analysis of the tests to the general ability of thestudents, two sections of the School and CollegeAbility Test were administered to the students inthe pilot groups. It turned out that the studentsin the pilot group in which the Series A and Series

B tests were tried out were definitely above thenational average in ability. Therefore, the Series

C tests were designed to be somewhat easier than

Series A and Series B so that they would be moreappropriate to use with less able groups. A special

effort was made to form the pilot groups for the

trial of the Series C tests from a more representa-tive section of the student population. These

groups also took the SCAT test, and an analysisshows that these Series C trial groups containstudents that are indeed representative of theaverage school population in the United States.

Laboratory TestsSince the laboratory forms an indispensible part

of the IPS course, and the success of the coursedepends on the ability of the student to skillfully

perform laboratory investigations and to interpretthem properly, it is appropriate to administer tests

to measure achievement in the laboratory.Limitations of time, space, and equipment usu-

ally require that the conduct of a laboratory testbe on a considerably less formal basis than that of

the Achievement Tests or the quizzes. The em-phasis should be on the actual technique adopted

and the reasoning involved in the investigation,rather than on the student's memory. All chemi-

cals and equipment used in the IPS course aremade available, and the student is permitted access

to his textbook and laboratory notebook. Like thelaboratory work itself, the laboratory tests are usu-ally performed by pairs of students, so that general

discussions are necessary. The teacher observesthe activity carefully, making notes to assist hisevaluation. When the test is complete, he baseshis final evaluation on the reasoning of the students

and the evidence they offer for their conclusions.

One of the laboratory tests the Sludge Testis lengthy, requiring about four or five labora-

tory periods; the students separate the components

of a complex mixture and describe them as accu-rately and completely as possible. Details aregiven in the Teacher's Guide; this test is appro-priate immediately following Chapter 5.

Three other laboratory tests are bound sep-arately, and are appropriate for use at later points

in the course. None consumes as much time as the

Sludge Test, two of them requiring about twolaboratory periods each, and each of the two parts

of the third requiring about one laboratory period.Suggestions about the grading of laboratory tests

are given in the booklet.

IPS Achievement TestsBy RAYMOND E. THOMPSONEducational Testing Service

Princeton, New Jersey

Achievement tests have been an integral partof IPS since the inception of the course. Preparedand revised by the same people who developedthe course, they provide a measure of student at-tainment of its objectives at several levels. Theperformance of an individual on a particular ques-

tion (one concept), the attainment of a class ona given test (a course segment), and the achieve-ment of a broad sample of students on an entireseries of tests (the course) are all measured.

There are now three series of IPS Achievement

Tests designated A, B, and C. The tests in series

A and B are intended for the typical student inIPS and are at the same level of difficulty.

The tests in series C are easier than those inseries A and B. In series A and B there are fourunit tests; each test is based on about three chap-ters of the IPS course and contains approximately30 objective questions. There are currently fourtests in series C, but a fifth test will be added.Each series C test deals with about two chaptersand contains approximately 25 objective ques-tions. Any of the tests can be administered inone class period of around 45 minutes.

The performance of samples of IPS students oneach of the test questions has been extensivelyanalyzed. These analyses showed for each ques-tion the proportion choosing each option and thecorrelation between success on the question andsuccess on the complete test in which the questionappeared. Furthermore, the number of studentsfrom each fifth (high to low) of the distributionin terms of score on the complete test who choseeach option was found. Finally, a measure of thecomplete test performance of those students choos-ing each option of the question was computed.

15

These statistics guided the selection and revision

of questions and made it possible to constructfinal forms of the tests with the desired difficultiesand discriminating powers.

Measures of the performances of IPS studentson earlier versions of tests in all three series arenow available. The data are presented in Table 1.The data for the tests in series A and B are basedon IPS students believed to be typical. The datafor the tests in series C are based on a sample of

lower-ability IPS students.The available tests are not identical to the ones

listed in this table, but have some questions elim-inated and others changed.

The statistics in Table 1 are based on rights-onlyscores. The reliability of a test is an index of theconsistency with which the test ranks and measuresstudents' performance. Reliability is a functionof a number of factors. It is maximized whenthe number of test questions is large, the diversityof the student group is great, the average difficulty

of the questions is 50 per cent, and the discrim-

inating power of the questions is high.For the same students on whom the data in

Ta ble IMeasures of Performance on IPS Achievement'Tests

Test

Series I 2 3 4

A Number of Students 1,818 1,632 1,170 370School Year '64-'65 '64-'65 '65-'66 '65-'66Chapters Covered 1-3 4-6 7-9 10-11

Number of Questions 26 30 30 30Mean Score 13.5 17.1 16.6 15.4

Standard Deviation 4.9 5.6 6.4 6.1

Reliability .80 .81 .87 .83

B Number of Students 2,785 2,405 1,990 195

School Year '66-'67 '66-'67 '66-'67 '67-'68Chapters Covered 1-3 4-5 6-8 9-11

Number of Questions 31 33 32 33

Mean Score 13.6 18.2 18.2 17-9

Standard Deviation 5.9 6.4 5.6 5.4

Reliability .82 .85 .83 .78

C Number of Students 425 400 165 320

School Year '67-'68 '67-'68 '67-'68 '67-'68Chapters Covered 1-3 4-5 6-7 8-9

Number of Questions 25 25 25 22

Mean Score 13.3 13.5 14.9 9.2

Standard Deviation 4.6 4.5 5.2 4.7

Reliability .77 .74 .83 .81

16

* .

Table 1 are based, the percentile sc iores n Table 2have been computed. Again, it should be notedthat the data for the series C tests are based onlower-ability IPS students.

Table 2Estimated Percentile Scores for IPS

Achievement Tests

Test

Series

A

Percentiles I 2 3 4

90 21 26 27 2575 18 22 23 2150 14 18 18 1625 10 15 12 1210 7 11 9 9

B 90 23 28 27 2675 19 24 24 2350 14 19 19 1925 10 14 15 1510 7 11 12 12

C 90 21 21 22 1775 18 18 20 1450 14 14 16 925 11 11 12 610 8 9 9 5

The students on whom the data for tests inseries A and B in Tables 1 and 2 are based camefrom a variety of schools and were taught by manydifferent teachers. Most were ninth-graders, butmany were eighth-graders; they represent a con-siderable range of academic ability. They are be-lieved to be typical of the students who weretaking IPS in the indicated school years.

The dependence of test performance on gradelevel and scholastic ability was studied in detail fora large group of students believed to be representa-

tive of IPS students in the 1965-66 school year.In that year 1,005 ninth-grade IPS students and400 eighth-grade IPS students took the School andCollege Abilities Test (SCAT), Survey Form, atest of verbal and mathematical ability. The resultsshown in Table 3 make it clear that these IPSstudents were more scholastically able on theaverage than typical junior high school studentsin the nation. .

Table 3 shows, for example, that a ninth-gradeIPS student who earned a SCAT converted scoreof 297 was placed at only the 50ih percentile inthis IPS grov, but at the 90th percentile in° thenational sample. cut another way, an IPS student

Table 3Scholastic Ability of IPS Students in the

1965-66 School Year

I

SCATGrade ConvertedLevel Score

9th 308302297290282

8th 306301295285276

ApproximatePercentile in

This IPS Group

9075502510

9075502510

ApproximatePercentile in

National Sample

9793907050

9897937540

who was superior to only half of this IPS groupin scholastic ability was superior to 90 per centof the national sample. These IPS students weresorted into six sub-groups on the basis of grade

Table 4Performances on IPS Tests (Series A) by Grade Level and Scholastic Ability

GradeScholastic

Ability

I

No. ofStudents

MeanScore

9

8

HighMiddleLow

HighMiddleLow

189398288

82110104

18.915.311.3

16.813.49.7

Test

No. ofStudents

206433310

578156

2 3 4

MeanScore

No. ofStudents

MeanScore

No. ofStudents

MeanScore

23.8 137 23.6 73 20.019.7 291 18.3 113 15.114.3 227 12.0 42 11.2

21.5 34 20.0 38 19.016.2 43 15.0 26 16.313.1 51 8.6 4 19.0

level and scholastic ability. The performances ofthese six sub-groups on the IPS Tests in series Aare indicat2d in Table 4.

The same criteria were used in sorting thestudents into six sub-groups for each test. For theninth-graders a percentile score on SCAT :I 80 orhigher in the IPS group (95 or higher in the na-tional sample) placed a student in the high sub-group; a percentile score of 30 or lower in theIPS group (80 or lower in the national sample)placed a student in the low sub-group. For theeighth-graders a percentile score on SCAT of 70or higher in the IPS group (95 or higher in thenational sample) placed a student in the highsub-group; a percentile score of 30 or lower inthe IPS group (80 or lower in the national sample)placed a student in the low sub-group.

Table 4 indicates that the higher the grade leveland the higher the scholastic ability of a student,the higher his performance on the IPS Tests canbe expected to be. There are only two exceptionsto this general trend. These exceptions are themean scores of eighth-grade students in the middleand low sub-groups on IPS Test 4. rlowever,these means are based on only 26 and 4 students,respectively, and they should probably be dis-counted.

The series C IPS Tests are designed for lower-ability students. A deliberate attempt was made toinclude easier and fewer questions in the series Ctests. The measures of test performance in Table1 for the series C tests are based on a group oflower-ability IPS students. In the 1967-68 schoolyear SCAT (Survey Form) was given to thisgroup of 511 lower-ability IPS students; nearlyall of these students were ninth-graders. Thescholastic ability of this group is indicated inTable 5.

Table 5Scholastic Ability of IPS Lower-Ability Ninth-

Graders in 1967-68 School Y ear

SCATConverted

Score

Approximate ApproximatePercentile Percentile in

in This IPS Group National Sample

295 90 93289 75 85283 50 70275 25 59267 10 25

17

Even this lower-ability IPS group was moreable than the national sample. But this group isdefinitely less able than the typical IPS studentsof 1965-66 whose scholastic ability is describedin Table 3.

I shall digress to describe an interesting littleexperiment that was done in 1968 on the effectof question placement within a test on student per-formance. Of special interest was the question ofwhether students were rushed toward the end ofthe test. Two forms of IPS Test 3 (Series C) wereprepared. In Form X the 25 questions appearedin one order; in Form Y the same 25 questionsappeared in essentially reverse order. That is, thefirst question in Form X was the last question inForm Y. Every other student in each class tookForm X; the remaining students took Form Y.The test performances of these two presumablyequ; valent groups of students on the two formsof the test are shown in Table 6.

Table 6Performance of Equivalent Groups on Two Forms

of IPS Test 3 (Series C)

Form X Form Y

Number of Students 165 155Mean Score 14.93 15.03Standard Deviation 5.16 4.63Reliability .83 .78

The mean scores of the two groups on the two ,

forms are not significantly different. In fact, onewould expect this difference due to chance alonemore than 80 times out 100. Furthermore, nosubstantial differences in performance on indi-vidual questions were found. For 17 of the ques-tions the percentage answering correctly in onegroup differed by 4 or less from the percentageanswering correctly in the other group; for sevenquestions the difference was between 5 and 10; andfor one question the difference was 12 percentagepoints. No indication of rushing was noted.

In summary, the test performances shown' inTable 1 on the series A and B tests are those oftypical IPS students, students considerably moreable on the whole than the average junior highsahool students in the nation. The performancesin Table 1 on the series C tests are those of lower-ability IPS students, students who are fairly typi-cal academically of junior high school students inthe nation.

Arm_,,,Ahha

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20

Approved IPS Apparatus

By JAMES A. WALTERIPS Group

Apparatus for use in Introductory Physical Sci-ence is developed in the laboratories of the Physi-cal Science Group of Education DevelopmentCenter and produced by independent manufac-turers. The unusual emphasis in the IPS programon laboratory experimentation as central to thelearning process has necessitated stringent stand-ards of performance in this apparatus. The amountthe student learns is related to the accuracy of theresults of his experiment, and therefore to thereliability of his instruments. Also, frequent useof laboratory equipment demands that it be safe.

For these reasons, EDC has instituted a series ofthorough inspections as the basis for EDC ap-proval of IPS apparatus. The inspection systemconsists of an initial inspection of the manufac-turer's product, followed by periodic inspections

thereafter.Over the past few years, the periodic and oc-

casional special inspections have been instrumentalin correcting faults and keeping the quality of

equipment at a high level. For example, the gran-ular copper for one experiment must have theproper grain size for a good reaction. Grains thatare too large give no resuks, and those that are toofine give toc rapid a reaction which is whyteachers must not use the electrolytic copper dust

for this experiment. One of the periodic inspectiontrips revealed that a supplier had switched fromgranular copper to small copper pellets tor this

item, a change which would have made the experi-

ment difficult or impossible to perform. In anothercase, it was discovered that the household am-monia solution supplied for an experiment con-tained soap, which made it unsatisfactory forIPS use.

The equal-arm balance has been given special

attention, since it is in many ways the backboneof the laboratory. A set of tests and specifications

was made up so that balances could be checked in

a uniform way. Fifteen wooden-arm balancesfrom the original production run were used to

establish a minimum performance level for an IPS

balance in several different tests. New balances

are expected to exceed these minimums. On sev-eral occasions it was found that balances beingproduced were below the minimum specifications.

In one case it was discovered that the agate bear-ings in use had too sharp a "V"; in another, theagates had a notch at the bottom of the "V," theresult of a regrinding operation that did not godeep enough.

Another case for quick action was revealed by

feedback from two teachers who had just receveda shipment of new balances. Since the teacherswere close by, a team from EDC inspected the bal-ances at the two schools and found that the tri-angular stock from which the fulcrums were cuthad very dull edges that impaired performance.

A check of balances at the factory showed thesame condition. Production was halted while newtriangular stock was obtained; replacements weremade in the kits at the warehouse, and new partswere sent out to schools which had received thefaulty material.

EDC approval of IPS apparatus is contingenton production of the complete line of IPS equip-

ment and the cooperation of the manufacturer withEDC in its inspection and evaluation progrqm.Any interested producer is welcome to participate.

The basic standard for approval of apparatusor chemicals is the question, "Can the experimentsas described in the IPS texts be performed withthese materials?" This gives the manufacturer theopportunity to take the apparatus and specifica-

tions as developed by EDC and initiate changes in

the end product. When prototypes have beendeveloped and tested, the company submits theapparatus and test results to EDC, where the itemis again tested and evaluated. When the prototypehas been approved, production begins and Anal

approval of the product is given only after aninspection of production items at the shippingpoint in the warehouse. Following this, the item

is spot-checked during periodic inspection, unlessfeedback suggests something has gone wrong and

a special check is required. If a design changeis to be made, this whole process is repeated inorder that the new design may go on the approved

list. After inspection of the initial product, spotchecks usually occur at one-year intervals, unless

innovations have been introduced in the apparatus,

in which case it is subjected to the complete in-

spection process.At intervals, the IPS group compiles and issues

THE PAPERBACK EDITION

Durables or

Consumables?By EDWARD A. JOHNSONAssistant Principal, Marblehead Junior High School

Marblehead, Massachusetts

Superintendents, principals, curriculum coordi-

nators, and school purchasing agents are again con-

fronted with one of those seemingly minor prob-

lems which call for a simple decision. Yet, as with

many "simple" decisions in education, this onecan have far-reaching effects.

As recently as five years ago, it would have beenconsidered unusual for many of the better sec-ondary schools in the country to have paperbacks

as basic texts. Today, most schools use paper-backs widely for both basic and supplementary

texts; librarians are now selecting a considerablepercentage of their orders from the soft-coverofferings. The importance of the consumable textis increasing in secondary schools and colleges all

over the country.At Marblehead Junior High School we believe

that for our purposes the value of a book is in itscontent. If we can put more quality materials into

the students' hands without substantially increasingthe long-term costs, we feel we owe it to the stu-dents, the teachers, and the taxpayers to do so.

The IPS course we offer at our school is a good

case in point. We prefer the paperbound to the

21

a status report on the equipment being produced

by the approved manufacturers. This list is made

available to all interested parties. Comments aremade on new items approved, items not approved

( if any), and suggestions to check on price where

deemed appropriate.The overall results of this approval system have

been to establish a good working relationship be-

tween EDC and the producers of IPS equipment,

and to maintain the high quality of the equipment

supplied for the course.

clothbound text because we feel that it offers

greater flexibility for both student and instructor.The text actually belongs to the student, so he isencouraged to annotate, to underscore, to compute

in the text as the instructor introduces new work

or discusses the results of labs just completed.We find that there is a tendency to take greater care

of the text when it is one's own. Students are urged

to keep the text for reference in later inductivecourses which follow IPS.

We feel that the educational advantages of offer-

ing the paperback text in this course far outweigh

the relatively small amount saved by purchasingthe clothbound edition for a longer term.

A Handy WorkbookBy ROBERT T. FITZGIBBONCurriculum CoordinatorGreece Central School District No. I

Rochester, New York

Over the five-year period during which IPS has

been used in Greece Central School District No. 1,

all of us who are directly involved with the pro-

gram have been asked many questions by inter-ested educators in other school districts. One ofthe most common questions relates to our decision

to use the soft-cover text.Obviously, this decision has resulted in a greater

financial obligation for the district. Why, then, use

the soft-cover when the program would still be the

22

same with the more permanent text? We, too,asked ourselves this basic question and decidedthat the program would not be the same with thehard-cover text. The rationale is as follows:

I. The paperback text is kept by the studentand becomes a handy record book.

2. The laboratory situation of IPS involves

a great deal of handling of the text. The

paperback format allows students to take

full advantage of this situation.3. We have seen the books used as reference

material in later science courses.4. With the paperback book, pre-lab hints

can be jotted down for easy reference.Notes on homework problems can be

recorded right in the book.5. With hard-cover texts, we have to worry

about youngsters entering data on graphs,

answers to questions, etc., that will inter-

fere with later use.6. Paperbacks eliminate problems of inven-

tory, storage, and collecting money for

lost or damaged books.

Fits the Philosophy

of IPSBy ARTHUR G. SUHRScience Chairman, Hamilton High School

Sussex, Wisconsin

In this school system the school district fur-

nishes all hard-bound textbooks, but studentsmust pm chase all paper-bound books. This factprompted the science teachers to select the paper-

back edition of the IPS text, since a part of the

philosophy of the science program in the Hamilton

schools is to encourage the student to design his

own laboratory procedures and data tables.In keeping with this philosophy, the science

teachers felt that no attempt should be made todiscourage students from using the textbook in any

manner they feel is helpful. Students are encour-aged to write notes in the text, underline importantsections, and write in answers to end-of-chapterproblems. They are told to use the book at thelab desks during the lab sessions directly with their

laboratory notebooks.

The teachel a try not to judge a student response

with a single right or wrong but rather use theresponse to guide students to answers consistent

with their observations and calculations. Students

are led to defend their answers before the class

during the lab and HDL discussions. Using their

texts as workbooks helps them to do this.Being encouraged to jot down notes, questions

and answers in the text is a new experience for

most students. In many it tends to create a newattitude toward their own importance to the class

and also tends to bring about student-centeredquestions and activities.

The paperback text therefore fits into the phil-

osophy of the IPS approach to science and is truly

one of the delights of the program.The Hamilton School System has used the IPS

materials since their general release in 1965. The

materials are used in both eighth and ninth grades

with approximately 375 students. The schoolbookstore sells the paperback edition at a mini-

mum mark-up. The total cost of the paperback is

less tho n that of the paperback laboratory guides

used in other science classes, and paperback books

used in other non-science classes.

Why I Like thePaperback EditionBy JOHN N. MEADENewman Junior High School

Needham, Massachusetts

"You mean it's mine?" "I can really keep it?"

"Can I write in it?" "Do I have to cover it?"Questions like these typify the reactions when

the paperback edition of IPS is passed out to stu-

dents every fall. School texts are not the mostcherished possessions of kids, but for some reason

this book receives care all year. I feel that thisattitude is a result of the integral part the bookplays in the course.

From an administrative point of view, using the

paperback edition reduces the time-consuming

task of numbering texts, checking, and then col-lecting them in June. The relatively low cost al-

lows me to provide each student with a new text

every year.

PHYSICAL SCIENCE II

The What and Why of PS IlBy URI HABER-SCHAIM

Work on the IPS program started in the earlymonths of 1963 with the object of producing aone-year course in physical science aimed pri-marily at the junior high school level. This goalremained in force during the years that followed.

However, as the use of IPS began to spread, ques-tions like "Where do we go from here?" and "Howabout more science in the same spirit?" were being

asked by teachers with increasing frequency. This

gave the impetus for discussions on the creation of

a course to follow IPS. What should be its pur-pose? For whom should it be designed, and whatshould its content be?

The first few trial years of the IPS programshowed that it was serving the two groups forwhich it was designed: students who plan to take

further courses in biology, chemistry, and/orphysics in senior high school, and those for whomthe IPS is followed only by biology.

In thinking about a follow-up course to IPS itwas decided right from the beginning that the newcourse should also be aimed at a broad spectrumof students, including those who would normallyterminate their science studies with biology. Twomajor topics were chosen for the course. They

can be summed up as (1) some of the funda-mentals of the chemistry and physics of electriccharge, and (2) forms of energy and the conser-vation of energy. Let us look at each of thesetopics in some detail.

In the IPS course the students investigate manyproperties of matter which pave the way for anintroduction to the atomic model. However, this

introduction is very limited: atoms come in differ-

ent kinds, they are small, and they are constantlymoving. Electrical phenomena were hardly studiedin IPS; therefore, there was no need to introduceelectric charge into the atomic model. For thestudent to appreciate the justification and powerof the extension of the atomic model to include

charge he must first investigate the relevant phe-

nomena.

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Here we face a problem: electrical gadgets are

familiar to all, but electric charge itself is notdirectly accessible to our senses as are mass,volume, or temperature. The indirectness of elec-

trical phenomena is probably responsible forsome deep-rooted misconceptions : almost all stu-dents starting PS II are convinced that when a carbattery is "dead" it is "discharged" and all theelectric charge in it has been consumed.

In electrical measurements the instruments are

more than extensions of the senses; they are thetools which provide the operational definitions of

the quantities with which we work. Since thecharge that flows rather than the rate of flow is of

primary concern to us, the first device used tomeasure the flow of charge is an electrolytic cell inwhich hydrogen is collected. With such cellsplaced at different points in a circuit, it is seenthat electric charge is not consumed, that it is

indeed conserved throughout the circuit. Once afirm feeling for the flow of charge has been estab-lished, the hydrogen cells are replaced by anammeter and a clock.

So far, all considerations have been in themacroscopic domain. Now we turn our attention

to electrolytic processes on the atomic scale andcompare the quantity of charge needed to release(or plate out) atoms of various elements. Theelectrolytic experiments lead to the idea of theelementary charge. They are then coupled to thepassage of charge through a vacuum and serve toexpand the atomic model to include ions andelectrons.

The development of these ideas also illustrates

our belief that the restudy of important materialin a new context or from a new point of view is an

effective way to increase comprehension and re-tention. In the IPS course we first introduced thelaw of constant proportions as a generalization ofexperience in the synthesis of compounds. Later inthe course, after the students have learned aboutatomic masses, we combine the knowledge of these

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masses and the empirically determined mass ratiofor forming a compound to arrive at molecularformulas. In PS II the law of constant proportionsis revisited, and the relation between the chargeper ion, atomic masses, and combining mass ratiois established.

The next topic which serves as a bridge to thestudy of energy is the heating effect of a flow ofcharge. The logic of the experiments done by thestudents can be summarized as follows: the quan-tity of heat produced in a resistor connected to agiven number of flashlight cells is proportional tothe charge that flows through it. When the numberof cells is varied, the heat per unit charge is pro-portional to the number of cells. The number ofcells is proportional to the voltage (i.e., what isread on a voltmeter). Therefore, the heat per unitcharge is proportional to the voltage, and the totalheat equals d constant times the product of chargetimes voltage (referred to as electrical work). Thisis the case when the charge flows through a heater,but is it always the case?

Before showing how we use the study of thisquestion as the means of getting at the idea ofenergy, it may be worthwhile to pause briefly andexplain why we searched for a new way to leadto such a seasoned concept. Although the detailsand the mathematical rigor vary, the main route toenergy in courses in Newtonian mechanics startsfrom kinematics, continues with forces and thelaws of motion to get to the subjects of work,kinetic energy, and potential energy, and ends withthermal energy and the conservation of energy.This is an arduous route for many students at anygrade level. There are several reasons for this:kinematics is rather abstract and conceptually dif-ficult, in particular when vector kinematics is in-cluded. The road is long and largely deductive,with few opportunities for leading experiments.Finally, as in much of physics and most of chemis-try and biology it is only the very end of the roadwhich is of interest; that is, energy transfers andenergy balance in a system are at the center of in-terest, whereas the details of the forces and thetemporal development of the system are ignoredor just not known.

For PS II we wanted an approach which startswith energy changes that are accessible to measure-ment and can, therefore, be operationally defined

without going first through the traditional develop-ment of Newtonian mechanics.

As was mentioned earlier, our starting point isthe question whether the electrical work alwaysequals the neat produced. By using an insulatedelectric motor as a calorimeter the students com-pare heat produced in the motor and electricalwork under three conditions of the motor: stalled,freely running, and weight-lifting. It is readilyestablished by experiment that in the last caseless heat is produced for the same amount of elec-trical work. However, the "missing" heat is re-covered by letting the weight fall slowly to itsoriginal position, turning the motor shaft and gen-erating heat in the motor as it falls.

The demonstration that less heat is produced bythe same amount of work when there are changesin the configuration of the system is repeated inseveral forms: less heat is produced in electrolyz-ing water than in plating copper in a cell contain-ing two copper electrodes. However, when hydro-gen and oxygca combine, the "missing" heat isrecovered.

Similarly, when a slowly falling weight is accel-erating a wheel, no heat is generated. But whenthe wheel is stopped the quantity of heat which isproduced equals that produced when the fallingweight generates heat directly by friction.

The complete cycle of missing heat and recov-ered heat shown in these experiments provides thereason for saying that changes in such diverse con-ditions as temperature, height, chemical composi-tion, or speed of a body are changes of the samekind; namely, changes in energy which comes indifferent forms.

This is as far as the course was developed andtried in the pilot schools during the first pilot year(1967-68). A revised Preliminary Edition is cur-rently being tried out on a larger scale.

We plan to continue the course with materialon the conservation of energy in general and pointout that while the law of conservation of energycan tell us what cannot happen, it is unable to pre-dict what will happen. We hope to conclude thecourse with a discussion (including experiments)which will lead to a qualitative understanding ofthe second law of thermodynamics from a statis-tical point of view. We believe that this ratheruntraditional topic should be included in this

k

"

f I

4 i **t

The heart of the motor experiments. The top half of the insulating box has been cut

away to show the position of the motor and thermometer.

course because the conversion of mechanical orelectrical energy to thermal energy is part andparcel of everyday processes around us.

PS ll in the Science CurriculumIt need hardly be mentioned that a two-year

sequence of physical science (either grades 8-9 orgrades 9-10) is not now part of the standard sci-ence curriculum in American schools. However,we believe that the general features of the mostcommon sequences in the present science programoriginated at a time when content and methodologyof the courses were very different from what theyare today. The sequence General Science and/orPhysical Science, Earth Science, Biology, Chemis-try, Physics had its origin at the time when phys-ical science touched lightly on everything. Earthscience was basically physical geography, biologywas descriptive botany and zoology, chemistrywas the zoology of the elements and their inorganiccompounds. Physics was moved to the 12th gradebecause it required more math than other subjects.

The chemistry required no prior knowledge ofphysics, and the biology required no prior knowl-edge of either chemistry or physics. In the con-text of those courses the sequence made sense.

During the last decade we have been witnessinggreat changes in the philosophy of science educa-tion and in the content and methodology of the

courses in the school. Modern chemistry requireia great deal of prior knowledge of physics, includ-ing twentieth-century physics. Earth science andbiology courses require quite sophisticated under-standing of physical and chemical principles andthe ability to apply them to complex systems. Sothere are good reasons for reversing the order ofthe three science courses in senior high school. Butthis by itself will not solve the problem, becauseof differences in enrollment in the three courses:almost all high school students take biology, abouthalf take chemistry, and only about one-fifth takephysics. Therefore, the majority of students do notget a sound basis in physical science either for theirgeneral education or for use in earth science orbiology. One year of physical science in juniorhigh school helps, but it is not enough. A secondyear of physical science is necessary.

To sum up, we envisage the IPS-PS II combina-tion as a possible foundation for several sequences,ranging from the minimum IPS, PS II, biology toa program for science-oriented students consistingof IPS, PS II, physics and/or chemistry, biologyand another year of biology or earth science.

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CONTENTS

Physical Science II

Chapter

11.* HEAT

Quantity of Heat: The Calorie . . . Experiment: Heating Different Substances. . . Heat Capacity; Specific Heat . . . Experiment: Heat Lost by a Substancein Cooling . . . Experiment: Heat Capacity and Specific Heat of a Solid . . .

Experiment: Heat of Reaction . . . Experiment: Heat of Solution . . . Experi-ment: Heat of Fusion . . . Heat of Vaporization . . . A Description of Heat ofReaction in Terms of Atoms . . . The Heat Capacity of Equal Numbers ofAtoms of Solid Elements

12. ELECTRIC CHARGE

Introduction . . . A Measure for the Quantity of Charge . . . Experiment: DoHydrogen Cells and Light Bulbs Consume Charge? . . . Experiment: Flowof Charge at Different Points in a Circuit . . . The Conservation of ElectricCharge . . . The Effect of the Charge Meter on the Circuit . . . Charge,Current, and Time . . . Experiment: Measuring Charge with an Ammeter anda Clock

13. ATOMS AND ELECTRIC CHARGE

The Charge Per Atom of Hydrogen and Oxygen . . . Experiment: The Elec-troplating of Nickel and Lead . . . The Elementary Charge . . . The Ele-mentary Charge and the Law of Constant Proportions . , . Experiment: TwoCompounds of Copper.. . . A New Look at the Law of Multiple Proportions

14. CELLS AND CHARGE CARRIERS

Experiment: The Daniell Cell . . . Experiment: Zinc and Copper in DifferentSolutions . . . Flashlight Cells . . . Unintentional Cells and Corrosion . . .

The Motion of Electric Charge Through a Vacuuni . . . Electrons . . . Atoms

and Ions . . . The Direction of Electric Current

*Since this cours is intended for students whohave had Introductory Physical Science in thepreceding year, the chapters have been num-bered consecutively beginning with partiallyrevised Chapter I I of the IPS text.

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15. HEAT AND ELECTRIC CHARGE

Experiment: The Heating Effect of a Flow of Charge : . . Experiment: HeatProduced as a Function of Number of Flashlight Cells . . . Experiment: TheVoltmeter.. . . Heat Produced as a Function of Voltage and Charge . . .

Electrical Work . . . Electrical Resistance . . . Experiment: Heat Producedin a Daniell Cell . . . The Relationship Between Electrical Work and Mass ofZinc Dissolved in a Battery

16. WHERE IS THE HEAT?

Heat Produced by an Electric Motor . . . Experiment: A Non-running Motor. . . Experiment: A Free-running Motor . . . Experiment: A Weight-liftingMotor . . . Experiment: Where Is the Missing Heat?

1 7. POTENriAL ENERGY

Gravitational Potential Energy and Thermal Energy. . . . Experiment: Gravi-tational Potential Energy as a Function of Mass . . . Experiment: Gravita-tional Potential Energy as a Function of Height . . . Heat Generated by aContracting Spring . . . Elastic Potential Energy

18. POTENTIAL ENERGY ON THE ATOMIC SCALE

A New Look at Heat of Vaporization . . . Atomic Potential Energy.. . . Experi-ment: Atomic Potential Energy and Atomic Separation in a Solution . . .

The Density of Sodium in a Solution of Sodium Nitrate . . . Atomic PotentialEnergy as a Function of Distance . . . Experiment: Heat Produced in theDecomposition of Water . . . Experiment: Heat Produced in a CopperPlating Cell . . . Further Comments on Atomic Potential Energy

19. KINETIC ENERGY

Experiment: Heat Generated by a Rotating Wheel . . . Another Form ofEnergy.. . . Kinetic Energy as a Function of Mass . . . Experiment: KineticEnergy as a Function of Speed . . . Kinetic Energy, Mass, and Speed . . .

A Re-examination of Experiments with Falling Weights . . . Thermal Energyof a Gas . . . A "Disc Gas" Machine . . . Experiment: The Effusion ofDifferent Gases

20-21 (IN PREPARATION)

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College Admissions and PS IIBy ELISABETH LINCOLNDana Hall SchoolWellesley, Massachusetts

Where does PS II fit into the secondary schoolcurriculum? One aspect of this question is whetherthe colleges will accept the combination of IPS andPS II as fulfilling their science requirement for ad-mission. To answer this question the college coun-selor at Dana Hall sent the following letter toabout 100 colleges in April 1968.

Letter to the Director of Admissions

Most Dana Hall students take Introduc-tory Physical Science (IPS) in the 9th or 10thgrades. In the current year our science clubhas piloted Physical Science II (PS II),which is an extension of IPS. We would liketo include it as part of our curriculum, butneed to know how such a course would beviewed for college admission. It is a coursedeveloped at the Education DevelopmentCenter (essentially the same group that de-veloped PSSC and IPS). In some cases nofurther science would be studied.* Wouldyou accept the combination of IPS and PS IIas fulfilling your science requirement of ad-mission?

This letter was accompanied by a descriptionof the PS II course prepared by Education De-velopment Center, and the following comments byour science department:

"The content of IPS and PS II together matchesneither a year of chemistry nor a year of physics.The concepts covered are very basic, with eachconcept derived from evidence in student experi-ments. The line of approach is to gather evidence,analyze the student data, formulate a conclusion,and use this information to develop a possiblemodel. Predictions can then be made and tested,

*This does not mean that we recommend only IPS andPS II; the Dana Hall School recommends that a studenttake one physical science and one biological science.Ideally, the non-science student will take IPS in 8th or9th grade, PS II in 9th or 10th grade, and biology in11th or 12th grade.

after which the model can then be modified and

added to."The conceptual degree of difficulty of PS II is

comparable to the material in a high school chem-istry or physics course. The combination of IPS

and PS II is a good physical science backgroundfor biology, and is a more unified program thanIPS followed by a year of chemistry."

A reply card was enclosed, which had the fol-lowing choices:

Will accept IPS and PS IIWill not accept IPS and PS IIWill consider on an individual basisWish to have more information.

Since Dana Hall is a girls' school, this mailingwas sent only to women's colleges and coeduca-tional institutions. The response showed that thefollowing colleges will accept IPS and PS II asfulfilling the science admission requirement, or insome cases counting as one science course whentwo are required:

Barnard Lawrence U.Beaver MacalesterBriar Cliff MarymountBryn Mawr Massachusetts U.

Carleton Miami U. (Ohio)Cazenovia MiddleburyCedar Crest Millikin

Centenary Mills

Chapman Mount VernonChatham New College

Colorado College New Hampshire U.Colorado U. New RochelleConnecticut College New York U.Denison North CarolinaDuke OberlinEmory Ohio WesleyanGoucher Pennsylvania U.Grinnell Pittsburgh U.Hollins PomonaHood RadcliffeKirkland RiponKnox Rochester U.

RockfordSt. LawrenceScrippsSmithSouthern California U.Syracuse U. (Buffalo)Temple Buell

The following collegesindividual basis:

American U.AntiochBeloitBradford JuniorColby JuniorDePauwDickinsonElmiraEndicott

VassarVermont U.Washington U. (Mo.)WellesleyWestern CollegeWisconsin U.Wooster

will consider on an

FinchHartwickJacksonLake ForestMariettaMary BaldwinSkidmoreWilson

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Will accept IPS and PS II except for engineer-ing programs:

Boston U. Denver U.Cornell Syracuse U.Carnegie Mellon

Will not accept IPS and PS II:Northwestern RollinsPine Manor

Desire more information:Colby

Sweet Briar

Manhattanville

Favorable letters but no commitment:Chicago U. Michigan U.Connecticut U. Mount Holyoke

As yet we have no experience with studentspresenting IPS and PS II for admission. Weanticipate this situation in the next several years,and in view of the positive response to our ques-tionnaire we plan to introduce PS II into ourcurriculum.

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How Do Students Respond to PS II?

By HAROLD PRATTScience CoordinatorJefferson County Public Schools (Colorado)

Why PS H? Where does it belong in our sci-ence curriculum sequence? Do we need thiscourse? These are the questions most often askedby school administrators and science teacherswhen the PS II course is described to them. Con-trast this reaction with the response of the eighth-graders in two schools in Jefferson County wherePS II was offered for the first time during the1967-68 school year as a part of the pilot pro-gram. In these two schools about 50 per cent ofthe students who had taken IPS in the eighthgrade indicated that they would prefer to takePS II in grade nine, instead of the earth sciencecourse (ESCP) normally offered in that grade.

In one school, Creighton Junior High, DonOsse, the IPS instructor, selected a group of thirtystudents for the class he and I were to teach jointly.Fifteen of the students were boys and fifteen weregirls. It soon became apparent that most of thestudents had requested PS II because of an interestin physical science that had been generated in theIPS class. It was also obvious that one or twowere in the class because they considered morephysical science to be less objectionable than earthscience.

After a quick, one-day review of IPS Chapters5 and 6, we started in earnest with Chapter 7.About one-third of the class had finished Chapter8 the previous year, but the others had endedthe year at various points in the course from theend of Chapter 6 to the middle of Chapter 8. Thiswas the result of the students having come from themany different classes of three IPS teachers. Thisis one of the first articulation problems that mustbe worked out in an IPS-PS II sequence.

Nine weeks later we were ready to begin Chap-ter 12. Some teachers might rush impatientlythrough this material to get on with the "new"course. But the new course begins almost any-where you please after Chapter 8. One strongreason for undertaking a second year of physical

science is that one year does not provide adequatetime to study many important topics carefully.For a majority of classes, some of the time will beused to complete chapters of the IPS course.

Except for the change in books, the switch toPS II was like starting any other new chapter. Thestyle and the logical "story line" continued as theyhad in IPS. As we proceeded through the newmaterial, it soon became obvious that while it wasvery revolutionary to us as instructors, it was nomore strange to the students than many of themore standard experiments of IPS, such as meltingpoint, density, etc. Their minds were not clutteredor distracted with standard experiments and con-cept development, as is the mind of the teachertrained in traditional experiments. This makes thepreparation of the teacher an absolute must in theimplementation of PS II. The experiments them-selves are unique, and the reasoning is so differentfrom any existing course that teachers need anopportunity to become acquainted with this newmaterial. (How many teachers have measured themissing energy in the electrolysis of water, or in aweight-lifting motor?) Many times we found our-selves wondering about the purpose of an experi-ment or puzzled about the reasoning involved in aseries of experiments.

The effect of IPS on the students was easilyobserved. The change in them provided a satisfy-ing contrast when we considered what the samestudents had been a year earlier. They now dis-played a marked improvement in their ability toset up an experiment and proceed with a minimumof instructions. From the beginning of the year,they were able to graph the results of an experi-ment with ease. Data would be recorded in theirnotebooks without specific instruction, and the stu-dents seemed to have more confidence in workingthe end-of-chapter problems than they did theyear before.

In both the Jefferson County pilot schools, it

was observed that the boys seemed to have anadvantage over the girls in working with theequipment and, in general, comprehending theideas involved. There appeared to be a differencehere that was not present in the first year of IPS.

I think part of the difference can be attributed tothe kinds of apparatus and ideas with which wewere dealing. The IPS course tends to be one inwhich the student heats, pours, and mixes thingsin test tubes, beakers, and evaporating dishes,while PS II tends more to connecting electric cir-cuits, running electric motors, and spinning bicyclewheels. The boys' advantage may be partly attrib-uted to a local curriculum sequence. All eighth-

grade boys are required to take a technical-voca-tional course in which they spend a large portionof their time in various shop, mechanical, andelectrical activities.

Our experience with PS II at this time does notprovide a single simple answer to the question ofwhere to place it in the science curriculum. The"why" of PS II has an easier answer. There areadditional important topics in physical science tobe studied beyond IPS, which many students are

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interested in and capable of studying without tak-

ing chemistry or physics.Is our present senior high school sequence of

biology, chemistry, and physics the best sequence?

Would two years of physical science in the juniorhigh school be an appropriate offering for somestudents? These questions seem as relevant as thequestion of where to use PS II. PS II places usin the happy, or frustrating, position of being able

to question our present curriculum by having analternative to present.

From its content and style, it seems clear thatPS II can be useful both to those who later enrollin physics or chemistry and to those who do not.For those students who will not enroll in physics

or chemistry, a good plan would be IPS in theninth grade followed by PS II in the tenth grade.Biology would then be offered in the eleventhgrade. For the future chemistry-physics students,

IPS and PS II constitute an excellent eighth andninth-grade sequence followed by the present high-school offerings. Other possible sequences couldbe suggested. Each would be designed to meetthe needs of a particular student.

In the Classroom:Frustrations and RewardsBy THOMAS J. DILLONConcord-Carlisle High School

Concord, Massachusetts

Continuing in the spirit of Introductory PhysicalScience, Physical Science II is a laboratory coursethat completely involves the student. Unlike the

first-year course, however, where the teacher, by

virtue of the material, plays a more passive rolethan is usually found in a science classroom, myexperiences with PS II found me in a much moreactive role.

The reason for this is twofold. Perhaps mostimportant is that I worked with a group of low-ability students. Even though they had completed

a year of IPS, their mathematical sophisticationand intellectual attitude were not always compat-ible with the demands of the course. Secondly, Isuspect that even for average and above-averagestudents the demands of the program are such

that more teacher direction is needed than was thecase with IPS. This is not to be construed as adeficiency. Indeed, the ideas in this program, al-though a bit more abstract than those in the first-

year course, are nevertheless fundamental ideas.Rather than gloss over these abstractions, (as we

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did in the old days with our chalk-board diagrams

of atoms, for example) the modern curriculum ad-

dresses itself to this very problem by making theabstractions as palatable as possible.

At least with my low-ability students, this active

role I played can be partially justified when oneconsiders the concepts involved. Where they were

used to "rice" numbers and units, like 30 mi/hr,for example, they were now asked to manipulateand digest quantities like 1.60 x 10-19 amp-sec/

atom of hydrogen. This kind of material can hardlybe self-taught. It takes quite a bit of "chalk talk"to make students realize that although the namesand numbers of the players may be different, thegame is the same. In some cases it took the whole

year for the student to realize this and to gainconfidence in his ability to make the mathematics

his servant and not his master. In a few cases,this reward was never to come.

The rewards, however, far outweigh the frustra-

tions. It is not difficult to excite kids when youimpress them with the fact that in their laboratorywork they will count atoms. (How can you count

things you can't el, en see?) It is not difficult toexcite kids when in an overview of the course youpoint out that there is an intimate relationship be-

tween the heating of a beaker of water in the firstchapter and spinning a bicycle wheel in a laterchapter. (Ridiculous!) It is not difficult to excite

kids when the very nature of the laboratory workrequires experimental techniques and sophisticated

data analyses that provoke a spirit of competition.

(It was even exciting to me to hr. ar an occasional

muffled cheer as individual team data were posted

for class analysis.) In short, the students responded

very favorably to the laboratory situation. Even

those who had difficulty with the mathematicalanalysis of the data saw a purpose in what they

were doing. They enjoyed the "detective story"atmosphere that was built into the lab program.(Where is the missing heat? Is the energy all ac-counted for?) Like the IPS, this course has a story

line that is soon spotted by the students. Theyhave to work very hard, and often harder than they

would like, to appreciate this point, but for thosewho can stick it out, the rewards are ample.

In conjonction with IPS, this course forms an

excellent two-year sequence in physical science.

Unquestionably it is a first-class preparation for

chemistry and physics. For students who may not

be science-oriented and probably would not go on

to chemistry and physics, the program also hasobvious merit. This two-year sequence in physical

science, followed by a year of biology, would com-

prise a very good science program for them. Inany event, regardless of the level of the students,the teacher who has been swept up by the spirit of

the new science offerings at all levels can be as-sured that Physical Science II will hold its ownwith any of them as a program that promises ten

busy fingers with a purpose.