The Scientific Method

The Skeptical Chemist

Robert Boyle

In “The Sceptical Chymist”

Boyle stated that scientific speculationscientific speculation was worthless unless it was supportedby experimental evidenceexperimental evidence.

This principle led to the development of the scientific methodscientific method.

(1661)

Scientific Method is a way to solve problems.

Do you have any problems to solve?

•Any big or any small ones?

Parts of the Scientific Method

• Identify a problem .• Research the problem• Make a hypothesis

(a testable prediction).• Experiment to test

the hypothesis.• Draw a valid conclusion.

Make observationMy car will not start

Make observationMy car will not start

Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 8

Scientific Method

ResearchLook in Books, ask neighbors, go on line

Car is out of gas Battery is deadBad alternatorBad solonoid

ResearchLook in Books, ask neighbors, go on line

Car is out of gas Battery is deadBad alternatorBad solonoid

Develop hypothesisIf the battery is DEAD then the carwill not start because there is no

electricity

Develop hypothesisIf the battery is DEAD then the carwill not start because there is no

electricity

A Scientific Experiment

procedure

the order of events

in an experiment;

the “recipe”

Experiments must be controlled; they

must have two set-ups that must differ

by only one variable.

The conclusion must be based on the data.

variable

any factor that

could influence

the result

DataObservations are also called data.

There are two types of data.

qualitative data quantitative data

descriptions; measurements; no numbers must have numbers

and UNITS

Identify the Qualitative and Quantitative Data

•Car lights dim when the battery is low•The battery produces 12 volts dc•The gas tank contains 5 gallons of gas•The green apples are acidic.•The solution contains 4 grams of sugar•The high frequency sound damages ears• High Brass contains at least 65% zinc

Make observationMake observation

ResearchResearch

Develophypothesis

Develophypothesis

Test hypothesis with an experimentReplace battery

Attempt to start the car

Test hypothesis with an experimentReplace battery

Attempt to start the car

Analyze data and drawConclusions

Car did not start

Analyze data and drawConclusions

Car did not start

Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 8

Scientific Method

Hypothesis is NOT

supported

Hypothesis is NOT

supported

Revisehypothesis

Revisehypothesis

Make observationMake observation

ResearchResearch

If we replace the alternator then it will startbecause it will convert mechanical energy

to electrical energy

If we replace the alternator then it will startbecause it will convert mechanical energy

to electrical energy

Test hypothesis with an experimentReplace the alternatorAttempt to start the car

Test hypothesis with an experimentReplace the alternatorAttempt to start the car

Analyze data and drawConclusionsCar starts

Analyze data and drawConclusionsCar starts

Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 8

Scientific Method

Hypothesis IS

supported

Hypothesis IS

supported

Test hypothesis with furtherexperiments

Test hypothesis with furtherexperiments

Make observationMake observation

Ask questionAsk question

Develophypothesis

Develophypothesis

Test hypothesis with an

experiment

Test hypothesis with an

experiment

Analyze dataand draw

conclusions

Analyze dataand draw

conclusions

Hypothesis IS

supported

Hypothesis IS

supported

Hypothesis is NOT

supported

Hypothesis is NOT

supported

Developtheory

Developtheory

Test hypothesis with furtherexperiments

Test hypothesis with furtherexperiments

Revisehypothesis

Revisehypothesis

Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 8

Scientific Method

Everyday ScienceScientific Method Making Spaghetti Sauce

Observation Spaghetti sauce should be red.

Hypothesis (prediction)

If I use tomato sauce it will be red.

Test Heat pot of tomato sauce.

Observe result Taste the sauce - bland.

Revise hypothesis? If I add garlic to tomato sauce it will not be bland

New test? Add garlic, taste - not so bland.

Conclusion The Final Recipe.

Then

And

QuestionQuestion

ResearchResearch

HypothesisHypothesis

Procedure/Method

Procedure/Method

DataData

ObservationsObservations

ConclusionConclusion

What does the scientist wantto learn more about?

What does the scientist wantto learn more about?

Gathering of informationGathering of information

An “Educated” guess of ananswer to the question

An “Educated” guess of ananswer to the question

Written and carefullyfollowed step-by-step

experiment designed to testthe hypothesis

Written and carefullyfollowed step-by-step

experiment designed to testthe hypothesis

Information collected duringthe experiment

Information collected duringthe experiment

Written description of whatwas noticed during the

experiment

Written description of whatwas noticed during the

experiment

Was the hypothesis correct or incorrect?

Was the hypothesis correct or incorrect?

Next

Then

Next

And

Finally

First

Scientific MethodA Review

An Apple a Day Keeps the Doctor Away

Does and an apple a day keep you healthy?

HypothesisIf you eat an apple a day then you will be healthy because

apples contain vitamins that help the body fight diseases.

Experiment

Have two very large groups of people testing. One group eats an apple a day the other does not eat apples.

Data

Track the health of each group for an extended period.

Conclusion

An Apple a Day Keeps the Doctor Away

From the side of your bed if aimed at his head

u

o

SCIENTIFIC METHOD

How do scientists do what they do?

Well, YOU know because you're a scientist, too!

Observation is an important part--

in fact it's the part at the very start.

For it's observation that causes you to wonder why earthworms do what they do and clouds form in the sky.

SCIENTIFIC METHOD

Your hypothesis is a "best guess" based on what you know about how things work--now you're ready to go!

Experimentation lets you test the hypothesis you've made--

to see if your best guess can make the grade.

And because variation is found in nature everywhere

SCIENTIFIC METHOD

repeated trials should be done, and done with care.

And don't forget to decide what variables you'll test.

You change the independent variables, but not the rest.

Recording your data is very important, too; so you can analyze the results and others can repeat what you do

SCIENTIFIC METHOD

When you've summarized your results and your experiment is done,

you'll have more information about nature and you'll have had some fun.

So, now you know that the scientific method is really cool, and that scientists don't just measure--they RULE!

The ScientificAttitude

The ScientificAttitude

“This attitude is one of inquiry, experimentation, honesty, and a faith that

all natural phenomena can be explained.”

“This attitude is one of inquiry, experimentation, honesty, and a faith that

all natural phenomena can be explained.”