Research Research Methods in Methods in

CSCSCohesion, Coherence, and Cohesion, Coherence, and

Emphasis Emphasis

in Scientific Writingin Scientific Writing

Coherence, Cohesion, and Coherence, Cohesion, and EmphasisEmphasis

Principles:Principles:

1.1. Put new information last (cohesion)Put new information last (cohesion)

2.2. Use passive voice judiciouslyUse passive voice judiciously

3.3. Make sure the first and last sentences of a paragraph match Make sure the first and last sentences of a paragraph match (coherence)(coherence)

Acknowledgement: Acknowledgement:

I based these slides mostly on Duke University Graduate I based these slides mostly on Duke University Graduate School Scientific Writing Resource at School Scientific Writing Resource at https://cgi.duke.edu/web/sciwriting (Coherence, Cohesion, and Emphasis), but I changed several examples to use computing concepts and terminology.

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Principle 1: Put new Principle 1: Put new information lastinformation last

Begin sentences with familiar (old) information Begin sentences with familiar (old) information establish context by linking to previous sentencesestablish context by linking to previous sentences avoid confusion requiring multiple readingsavoid confusion requiring multiple readings make the writing cohesive (sentences stick make the writing cohesive (sentences stick

together)together)

Conclude sentences with unfamiliar (new) Conclude sentences with unfamiliar (new) informationinformation introduce new ideas or characters in contextintroduce new ideas or characters in context seek clarityseek clarity emphasize new information at endemphasize new information at end

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Put new information Put new information lastlast

ExampleExample

Farmers try to provide optimal growing Farmers try to provide optimal growing conditions for crops by using soil additives conditions for crops by using soil additives to adjust soil pH. Garden lime, or to adjust soil pH. Garden lime, or agricultural limestone, is made from agricultural limestone, is made from pulverized chalk, and can be used to raise pulverized chalk, and can be used to raise the pH of the soil. Clay soil, which is the pH of the soil. Clay soil, which is naturally acidic, often requires addition of naturally acidic, often requires addition of agricultural lime.agricultural lime.

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Put new information Put new information lastlast

Example annotated with Example annotated with old old and and newnew::

Farmers try to provide optimal growing conditions Farmers try to provide optimal growing conditions for for crops by using crops by using soil additives to adjust soil pHsoil additives to adjust soil pH. .

Garden lime, or agricultural limestoneGarden lime, or agricultural limestone, is made from , is made from pulverized chalk, and can be used to pulverized chalk, and can be used to raise the pH of the raise the pH of the soilsoil. .

Clay soilClay soil, which is naturally acidic, often requires , which is naturally acidic, often requires addition of addition of agricultural limeagricultural lime..

Sentence 2 introduces Sentence 2 introduces ““garden limegarden lime”” with little context: with little context: lime as citrus fruit? or as soil additivelime as citrus fruit? or as soil additive

Sentence 3 introduces Sentence 3 introduces ““clay soilclay soil”” with little context: itself with little context: itself an additive? or needing additive?an additive? or needing additive?

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Put new information Put new information lastlast

Original:Original:

Farmers try to provide optimal growing conditions for Farmers try to provide optimal growing conditions for crops by using soil additives to adjust soil pH. Garden crops by using soil additives to adjust soil pH. Garden lime, or agricultural limestone, is made from pulverized lime, or agricultural limestone, is made from pulverized chalk, and can be used to raise the pH of the soil. Clay chalk, and can be used to raise the pH of the soil. Clay soil, which is naturally acidic, often requires addition of soil, which is naturally acidic, often requires addition of agricultural lime.agricultural lime.

Rewrite:Rewrite:

Farmers try to provide optimal growing conditions for Farmers try to provide optimal growing conditions for crops by using soil additives to adjust soil pH. One way crops by using soil additives to adjust soil pH. One way to raise the pH of the soil is an additive made from to raise the pH of the soil is an additive made from pulverized chalk called garden lime or agricultural pulverized chalk called garden lime or agricultural limestone. Agricultural limestone is often added to limestone. Agricultural limestone is often added to naturally acidic soils, such as clay soil.naturally acidic soils, such as clay soil.

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Put new information Put new information lastlast

Rewrite:Rewrite:

Farmers try to provide optimal growing conditionsFarmers try to provide optimal growing conditions for for crops by using crops by using soil additives to adjust soil pHsoil additives to adjust soil pH. .

One way to One way to raise the pH of the soilraise the pH of the soil is an additive made is an additive made from pulverized chalk called from pulverized chalk called garden lime or agricultural garden lime or agricultural limestonelimestone. .

Agricultural limestone Agricultural limestone is often added to naturally acidic is often added to naturally acidic soils, such as soils, such as clay soilclay soil..

Each sentence Each sentence ““leans forwardleans forward”” from old to new information from old to new information

Paragraph becomes more cohesiveParagraph becomes more cohesive

New information emphasizedNew information emphasized

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Put new information Put new information lastlast

Revision technique:Revision technique:

Read through your manuscript carefully. In Read through your manuscript carefully. In each sentence, underline any pieces of new each sentence, underline any pieces of new information (unfamiliar to the reader at this information (unfamiliar to the reader at this point in the manuscript). Make sure your point in the manuscript). Make sure your sentences begin with an appropriate sentences begin with an appropriate backwards link, and not with an unfamiliar backwards link, and not with an unfamiliar concept.concept.

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Principle 2: Use passive voice Principle 2: Use passive voice judiciously judiciously

Active voice sentence:Active voice sentence:Subject Verb ObjectSubject Verb Object

Subject Verb Subject Verb

Subject Subject is actor, is actor, Verb Verb is action, is action, Object Object is acted is acted uponupon

Passive voice sentence:Passive voice sentence:

Object Verb SubjectObject Verb Subject

Object VerbObject Verb

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Use passive voice Use passive voice judiciouslyjudiciously

Active:Active:

The payroll program prints the paychecks twice a month.The payroll program prints the paychecks twice a month.

subject = program, verb = prints, object = subject = program, verb = prints, object = paycheckspaychecks

Passive:Passive:

The paychecks are printed by the payroll program twice a The paychecks are printed by the payroll program twice a month.month.

switches positions of subject and objectswitches positions of subject and object

The paychecks are printed twice a monthThe paychecks are printed twice a month..

leaves out subject (actor) entirelyleaves out subject (actor) entirely

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Use passive voice Use passive voice judiciouslyjudiciously

Passive voice is grammatically correct and Passive voice is grammatically correct and often useful but used excessively in often useful but used excessively in scientific writingscientific writing

Misconceptions:Misconceptions:

✖✖ Passive voice is inherently scientificPassive voice is inherently scientific

✖✖ Passive voice is more objectivePassive voice is more objective

✖✖ Writers should avoid first person pronounsWriters should avoid first person pronouns

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Use passive voice Use passive voice judiciouslyjudiciously

Using first-person pronouns?Using first-person pronouns?

Active voice livelier, easier to readActive voice livelier, easier to read

Myth that avoiding first-person gives more Myth that avoiding first-person gives more objectivityobjectivity

You did the work—to imply otherwise is You did the work—to imply otherwise is misleadingmisleading

Results did not magically appearResults did not magically appear

All authors must take responsibility for All authors must take responsibility for paperpaper’’s contents content

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Use passive voice Use passive voice judiciouslyjudiciously

(A) Problem with passive voice – actor is often (A) Problem with passive voice – actor is often ambiguousambiguous

Common to leave out actor in scientific Common to leave out actor in scientific writing (i.e., Object Verb)writing (i.e., Object Verb)

Can lead to confusion if difficult to determine Can lead to confusion if difficult to determine actoractor

Acceptable when actor is self-explanatory, Acceptable when actor is self-explanatory, understood, or unimportant – e.g., when understood, or unimportant – e.g., when describing methodsdescribing methods

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Use passive voice Use passive voice judiciouslyjudiciously

Example of ambiguous actor (from Zobel textbook, p. Example of ambiguous actor (from Zobel textbook, p. 14):14):

The following theorem can now be proved.The following theorem can now be proved.

Rewrite:Rewrite:

We can now prove the following theorem.We can now prove the following theorem.

Direct (active) style is less stilted, easier to readDirect (active) style is less stilted, easier to read

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Use passive voice Use passive voice judiciouslyjudiciously

Example of ambiguous actor:Example of ambiguous actor:

The web application was designed using the Model-View-The web application was designed using the Model-View-Controller (MVC) architectural pattern (Reenskaug et al Controller (MVC) architectural pattern (Reenskaug et al 2009).2009).

Who designed the application? Was it Reenskaug et al? Or Who designed the application? Was it Reenskaug et al? Or did they develop MVC?did they develop MVC?

Rewrites?Rewrites?

The team designed the web application using the Model-The team designed the web application using the Model-View-Controller architectural pattern (Reenskaug et al View-Controller architectural pattern (Reenskaug et al 2009).2009).

The team used the Model-View Controller architectural The team used the Model-View Controller architectural pattern (Reenskaug et all 2009) to design the web pattern (Reenskaug et all 2009) to design the web application. application.

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Use passive voice Use passive voice judiciouslyjudiciously

(B) Problem with passive voice – dangling modifiers(B) Problem with passive voice – dangling modifiers

Dangling modifier: modifying phrase whose Dangling modifier: modifying phrase whose implicit subject does not match explicit subject implicit subject does not match explicit subject of sentenceof sentence

Considered grammatical error in modern English Considered grammatical error in modern English usageusage

Occurs frequently in scientific writing, almost Occurs frequently in scientific writing, almost acceptedaccepted

Confuses reader, so avoid itConfuses reader, so avoid it

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Use passive voice Use passive voice judiciouslyjudiciously

Example of dangling modifier:Example of dangling modifier:

Using the Strategy design pattern, the Using the Strategy design pattern, the specific sorting algorithm can be selected at specific sorting algorithm can be selected at runtime.runtime.

““Using the Strategy design patternUsing the Strategy design pattern”” has has implied subject implied subject ““the programmersthe programmers””..

But the implicit subject of passive sentence But the implicit subject of passive sentence is is ““the programthe program”” or maybe or maybe ““the usersthe users””

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Use passive voice Use passive voice judiciouslyjudiciously

Original:Original:

Using the Strategy design pattern, the specific sorting Using the Strategy design pattern, the specific sorting algorithm can be selected at runtime.algorithm can be selected at runtime.

Rewrites?Rewrites?

Using the Strategy design pattern, the programmers Using the Strategy design pattern, the programmers designed the program to select the specific sorting designed the program to select the specific sorting algorithm at runtime.algorithm at runtime.

Using the Strategy design pattern, the programmers Using the Strategy design pattern, the programmers designed the program to enable users to select the specific designed the program to enable users to select the specific sorting algorithm at runtime.sorting algorithm at runtime.

The programmers used the Stategy design pattern in the The programmers used the Stategy design pattern in the program design. This enabled the users to select the program design. This enabled the users to select the specific sorting algorithm at runtime.specific sorting algorithm at runtime.

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Use passive voice Use passive voice judiciouslyjudiciously

(C) Problem with passive voice – wordiness (C) Problem with passive voice – wordiness

If everything else is equal, shorter writing is If everything else is equal, shorter writing is better than longerbetter than longer

Readers benefit if they have less to read to get Readers benefit if they have less to read to get same informationsame information

Passive voice tends to increase length slightlyPassive voice tends to increase length slightly

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Use passive voice Use passive voice judiciouslyjudiciously

Example (Zobel, p. 14):Example (Zobel, p. 14):

Tree structures can be utilized for dynamic storage of terms.Tree structures can be utilized for dynamic storage of terms.

Implicit actor, weak verb Implicit actor, weak verb ““utilizedutilized””, concept noun , concept noun ““storagestorage””, 10 w0rds, 10 w0rds

Rewrites:Rewrites:

Terms can be stored in dynamic tree structures.Terms can be stored in dynamic tree structures.

Still passive, more precise verb Still passive, more precise verb ““storedstored””, 7 words, 7 words

The program stored terms in dynamic tree structures.The program stored terms in dynamic tree structures.

Explicit actor in subject, 8 wordsExplicit actor in subject, 8 words

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Use passive voice Use passive voice judiciouslyjudiciously

Advantage of passive voice:Advantage of passive voice:

Changes order of sentence, so can help put old Changes order of sentence, so can help put old information before newinformation before new

Revision technique:Revision technique:

When you revise for new/old information placement, When you revise for new/old information placement, use active/passive switching to keep the placement use active/passive switching to keep the placement of information consistent with expected structure.of information consistent with expected structure.

But be careful with ambiguity, providing actors to But be careful with ambiguity, providing actors to avoid confusionavoid confusion

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Principle 3: Make sure first & last Principle 3: Make sure first & last sentences of paragraph match sentences of paragraph match

Coherence:Coherence:

Readers expect thoughts expressed in Readers expect thoughts expressed in paragraph unitsparagraph units

Paragraphs correspond to single thoughtParagraphs correspond to single thought

Each sentence supports that thoughtEach sentence supports that thought

Along with cohesion, maintains logical flowAlong with cohesion, maintains logical flow

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Make sure first & last sentences of Make sure first & last sentences of paragraph match paragraph match

Example of paragraph that is cohesive, but not Example of paragraph that is cohesive, but not coherentcoherent

MMy favorite animal is the domestic cat. Cats were y favorite animal is the domestic cat. Cats were domesticated almost 10,000 years ago in ancient domesticated almost 10,000 years ago in ancient Mesopotamia. Mesopotamia is a name that literally Mesopotamia. Mesopotamia is a name that literally means "the land between two rivers," taken from means "the land between two rivers," taken from Greek. The Greek language is one of the oldest Greek. The Greek language is one of the oldest written languages, and its alphabet forms the basis written languages, and its alphabet forms the basis of many other writing systems, including Latin. of many other writing systems, including Latin. Latin ...Latin ...

Topic wanders from cats to Mesopotamia to the Greek Topic wanders from cats to Mesopotamia to the Greek language to the Latin language, etc. Not coherent!language to the Latin language, etc. Not coherent!

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Make sure first & last sentences of Make sure first & last sentences of paragraph match paragraph match

Revision techniqueRevision technique

Test for coherence: Read the first and last Test for coherence: Read the first and last parts of each paragraph. Do the topics parts of each paragraph. Do the topics match? To be more thorough, make sure each match? To be more thorough, make sure each sentence in a paragraph supports the main sentence in a paragraph supports the main point of that paragraph.point of that paragraph.

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Example 1Example 1

Detecting security vulnerabilities at the code level has been a Detecting security vulnerabilities at the code level has been a subject of considerable interestsubject of considerable interest..

Readers naturally emphasize end of sentences.Readers naturally emphasize end of sentences.

What do we want to emphasize? Probably either ”security What do we want to emphasize? Probably either ”security vulnerabilities" or “code levelvulnerabilities" or “code level”” -- depending on the point of -- depending on the point of the paper.the paper.

Rewrite to emphasize the code level:Rewrite to emphasize the code level:

One subject of considerable interest has been detecting One subject of considerable interest has been detecting security vulnerabilities at the code level.security vulnerabilities at the code level.

Rewrite to emphasize security vulnerabilities:Rewrite to emphasize security vulnerabilities:

One subject of considerable interest at the code level has One subject of considerable interest at the code level has been detecting security vulnerabilities. been detecting security vulnerabilities.

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Example 2Example 2

Improvements are expected in the predictive Improvements are expected in the predictive power of all the scores being computed on power of all the scores being computed on the clickstreams.the clickstreams.

Has two passive-like verbs: are expected, Has two passive-like verbs: are expected, being computedbeing computed

Eliminating those, turning Eliminating those, turning ““improvementimprovement”” into into verb, yields revisionverb, yields revision

Our method will improve the predictive Our method will improve the predictive power of all clickstream scores.power of all clickstream scores.

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Example 3Example 3

A A survey is given of differential expression analyses survey is given of differential expression analyses using the linear modeling features of the package.using the linear modeling features of the package.

Relies on passive voice, leading to awkwardnessRelies on passive voice, leading to awkwardness

““a survey is given ofa survey is given of”” is difficult to parse is difficult to parse

Does Does ““usingusing”” modify survey or analyses? modify survey or analyses?

Rewrites?Rewrites?

We use the linear modeling features of the package to We use the linear modeling features of the package to survey differential expression analyses.survey differential expression analyses.

We survey differential expression analyses that use the We survey differential expression analyses that use the linear modeling features of the package.linear modeling features of the package.

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Example 4Example 4

By typing alphabetic characters in the text box, By typing alphabetic characters in the text box, the Web application was demonstrated to the Web application was demonstrated to charge the customercharge the customer’’s credit card incorrectly.s credit card incorrectly.

Relies on passive voice with unspecified actorRelies on passive voice with unspecified actor

Has a dangling modifierHas a dangling modifier

Rewrite eliminating passive in the main clause:Rewrite eliminating passive in the main clause:

By typing alphabetic characters in the text box, By typing alphabetic characters in the text box, the test team showed that the Web application the test team showed that the Web application incorrectly charged the customerincorrectly charged the customer’’s credit card.s credit card.

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Example 5Example 5

Science is a system for accumulating Science is a system for accumulating reliable knowledge. Speculation, reliable knowledge. Speculation, observation, and a growing understanding observation, and a growing understanding of some idea or phenomenon, broadly of some idea or phenomenon, broadly speaking, begin the process of science.speaking, begin the process of science.

(constructed from passage in Zobel (constructed from passage in Zobel textbook, p. 3)textbook, p. 3)

Second sentence Second sentence begins with new information begins with new information

”speculation, …”speculation, …”” has old information “process of sciencehas old information “process of science””

laterlater complex subject, separated from verbcomplex subject, separated from verb

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Example 5Example 5

Science is a system for accumulating reliable Science is a system for accumulating reliable knowledge. Speculation, observation, and a growing knowledge. Speculation, observation, and a growing understanding of some idea or phenomenon, broadly understanding of some idea or phenomenon, broadly speaking, begin the process of science.speaking, begin the process of science.

Simplify the subject, decrease subject-verb Simplify the subject, decrease subject-verb distance, put new information last:distance, put new information last:

Science is a system for accumulating reliable Science is a system for accumulating reliable knowledge. Broadly speaking, the process of science knowledge. Broadly speaking, the process of science begins with speculation, observation, and a growing begins with speculation, observation, and a growing understanding of some idea or phenomenon.understanding of some idea or phenomenon.

Second sentence now hasSecond sentence now has backwards link to the previous sentence (old backwards link to the previous sentence (old

info.)info.) less complex subjectless complex subject reduced subject-verb distancereduced subject-verb distance

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