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WRITING A SCIENTIFIC PAPERMaximizing the Potential for Publication

Arthur M. Winer, Ph.D.Distinguished Professor Emeritus

Environmental Health Sciences DepartmentSchool of Public Health

University of California, Los Angeles

Portions adapted from a presentation by Professor Hans LambersSchool of Plant Biology

The University of Western AustraliaPerth, Australia

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Data that have not been publishedData that have not been published do not exist! do not exist!

If you do not publish your data, you might as well not do the experiments

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Where to publish?Where to publish?

• Carefully select the right journal– From which journals do you cite papers in your

reference list?– Which journals publish on a similar topic?

• Final decision– Prestige (“impact factor”)– Time to publish (check time between submissions of

manuscripts and publication)– Experience with a specific journal (attitude of

reviewers and editors)– Page charges

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The Structure of a Scientific PaperThe Structure of a Scientific Paper• Authors + addresses• Title, running title• Abstract• Keywords, abbreviations• Introduction• Materials and methods• Results• Discussion• Conclusion• Acknowledgments• References• Tables and Figures

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Begin with the Results SectionBegin with the Results Section

• Arrange your data in figures and tables– Are the data best presented as figures or as

tables?• Decide which figure/table comes first• Decide the order of all other figures/tables• Make a structure for your Results

– Decide what you wish to describe– Design the sections in the Results (bullet

points)• Decide what you wish to describe in each

section• Then start writing

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The Style in the Results SectionThe Style in the Results Section

• Write your results in the past tense• Avoid double negatives

– The rate of photosynthesis was not very fast.

– The rate of photosynthesis was slow.• Use the active voice

– This rule does not mean that you should entirely discard the passive voice

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The choice between a FigureThe choice between a Figure or a Table or a Table

Age malic malonic lactic acetic maleic citric cis-aconiticsuccinic fumaric trans-aconiticTotal0 161 0 371 0 0 119 109 0 7 484 1252

1.5 0 0 66 0 0 0 4 0 2 14 862.5 17 0 41 0 0 0 1 0 4 5 685.5 21 0 0 0 0 0 0 0 0 6 278.5 929 0 0 57 0 824 6 209 22 19 2066

13.5 3217 0 0 0 0 3020 14 160 7 54 647125 0 0 11 0 0 0 0 0 0 0 11

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0 10 20 30

Time (days)

OA

(nm

ol g

-1 F

W s

-1)

malic

malonic

lactic

acetic

maleic

citric

cis-aconitic

succinic

fumaric

trans-aconitic

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The choice between a few lines in The choice between a few lines in the text or a Tablethe text or a Table

The yield of rice was 1.23, 2.79, 3.19, 1.01 and 4.27 ton ha-1 for the farms of Dore, Zhang,

Carly, West and Shen, respectively

Dore Zhang Carly West Shen1.23 2.79 3.19 1.01 4.27

These results are easier to grasp when presented in a Table

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Can we make the table clearer by Can we make the table clearer by altering the axes?altering the axes?

Dore Zhang Carly West Shen1.23 2.79 3.19 1.01 4.27

Dore 1.23

Zhang 2.79

Carly 3.19

West 1.01

Shen 4.27

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Should we order the data in a Should we order the data in a different manner?different manner?

Carly 3.19

Dore 1.23

Shen 4.27

West 1.01

Zhang 2.79

Arrange alphabetically?

No improvement!

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Should we order the data in a Should we order the data in a different manner?different manner?

West 1.01

Dore 1.23

Zhang 2.79 Carly 3.19

Shen 4.27

Arrange in order of increasing yield?

Shen did much better than any of the others

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Is this level of precision justified?Is this level of precision justified?

West 1.01

Dore 1.23

Zhang 2.79

Carly 3.19

Shen 4.27

West 1.0

Dore 1.2

Zhang 2.8

Carly 3.2

Shen 4.3

Include as many decimal points as justified by the accuracy of your data

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The columns of a table must be labelled The columns of a table must be labelled appropriately, and the units must be appropriately, and the units must be

included tooincluded too

West 1.1

Dore 1.2

Zhang 2.8

Carly 3.2

Shen 4.3

Farmer Yield (ton ha-1)

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We can quickly see why the yield on We can quickly see why the yield on Shen’s farm was so high:Shen’s farm was so high:

optimum pH! optimum pH!

Farmer Yield(ton ha-1)

Average soil pH

West 1.1 4.1

Dore 1.2 4.2

Zhang 2.8 5.0

Carly 3.2 5.4

Shen 4.3 6.1

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Would a Figure have been better Would a Figure have been better in this example?in this example?

I don’t really think so, but it is a matter of opinion

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Would lines, connecting the data points have Would lines, connecting the data points have been a good idea? or perhaps regression lines?been a good idea? or perhaps regression lines?

Never connect data points, if the data on the x-axis are not Never connect data points, if the data on the x-axis are not “scaled” – regression lines would have been a mistake!“scaled” – regression lines would have been a mistake!

x

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All figures and tables require All figures and tables require appropriate legendsappropriate legends

• Describe what is shown• Do not discuss what is shown• Explain acronyms, if you use any in figures or

table– Even when you use the same abbreviations

throughout text– WUE = water-use efficiency

• Explain errors bars: SE or SD; add n (number of observations)

• Explain meaning of statistical information

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ResultsResults• Figure 1

– Describe what it shows– Number figures in order of

appearance in the text• Table 1

– Describe what it shows• Lead the reader through your data

– From one Figure (Table) to the next

• Arrange a logical flow from section to section

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Then Continue Writing Then Continue Writing the Discussionthe Discussion

• Make a structure for your Discussion– Decide what you wish to discuss– Design the sections in the Discussion (bullet points)

• Then make a structure for each section (bullet points)– Decide what you wish to describe in each section

• Place your results in a wider context• Compare your results with those in the literature • Then start writing• Finish with a paragraph in which you tell the reader

what are the main points (“take-home-message”) and why you work is important

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ConclusionConclusion

• Paper may, or may not, have a Conclusion(s) section

• Survey papers in the journal

• Summarize key findings and their implications

• Recommend future research, if appropiate

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Materials and MethodsMaterials and Methods

• Once you know which data you will include, you write up all the Materials and Methods used to acquire the data

• Include all relevant details• Methods

– Provide sufficient detail for someone else to reproduce your work

• Equipment, chemicals, instruments– Manufacturer, city, country

• Experimental conditions or models• Be precise

– “Room temperature” is not an accurate description

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IntroductionIntroduction

• Briefly review the literature relevant for your manuscript (use your Discussion as a guideline)

• Do not just write this Introduction for half a dozen colleagues working in exactly the same field, but…

• Write for a range of interested scientists• Finish with the aims of your work and present

a clear hypothesis

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ReferencesReferences

• Cite in a “balanced” manner and do not ignore specific groups

• Avoid too many references to the work of yourself or your group

• Cite the primary literature, if referring to a key finding

• Cite a review, if you wish to refer to a fact that has been found by numerous authors

• Cite textbooks only when referring to generally accepted knowledge

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AcknowledgementsAcknowledgements

• Acknowledge the input of people and agencies who allowed you to conduct this research and write this manuscript

• Your supervisor (if not a co-author)• Students, technicians (if not co-authors)• Colleague who gave you bright ideas or critically

read your manuscript• Anyone else who helped you in a meaningful way• Granting agencies• Others

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Title

• Should cover the main aims and/or message

• Should appeal to your audience

• Should not be too long

• Avoid titles with a numbered subtitle– Subtitles may get lost, and hence your

paper may not be found in searches

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Running Title

• A journal may require a subtitle• It cannot exceed a certain number of characters

– check instructions for authors of the journal• Should cover the main aims and/or message• It is an abbreviated version of your title• It is only printed above some pages of your

paper• It is not used for literature searches• It is therefore less important than a good title• Use your title as a guideline

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AbstractAbstract

• Should contain the aim of your research

• Do not use references in the abstract

• If you must use them, then all details must be there (as in the references list, but without the title) because an abstract must stand on its own

• Make sure the main results, conclusions, and take-home-messages are there

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Who are the authors and their Who are the authors and their addresses?addresses?

• Make sure all authors read your manuscript before you submit it

• Never add an author who has not contributed or read the manuscript

• Include the name of the institute/laboratory where the work was done as the first address

• If an author has moved, add their “present address”

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What is the order of the authors of What is the order of the authors of your paper?your paper?

• The person who did the work and wrote the manuscript should be first (=senior) author

• Corresponding author is the one that will be the contact for the journal and correspondence that may follow after publication

• Senior author and corresponding author can be the same

• The research-team leader (often the corresponding author) appears as the last author

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Frequently made mistakesFrequently made mistakes • Invalid statistics

– Presenting linear regressions when one axis is not scaled (e.g., sites, species, farmers)

• Units lacking in tables or figures• Incorrect units:

– s (= seconds) instead of S (= Siemens) – Kg instead of kg– Units of time must appear at the end

• mmol s-1 m-2 should be mmol m-2 s-1 – ug, umol and uM, instead of g, mol and M– mM L-1 should be mmol L-1

• mM is short for mmol L-1

• No numbers or legends for tables or figures

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Frequently made mistakesFrequently made mistakes (cont’d)

• Too many significant figures• Cited references not given in reference list• Incorrect/sloppy style of referencing• The data shows … (instead of the data show ….)• Anthropomorphic reasoning

– “plants attempt…”• Too many decimal places

– 0.239876 (SE = 0.052501) should be 0.23 (SE = 0.05)• No space between values and units, or between different

units– 20m; should be 20 m (but 20% should, indeed, be 20%)– 10mmolm-2s-1; should be10 mmol m-2 s-1

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Something you must never doSomething you must never do

• Never copy whole sentences or paragraphs without referring to the original text

• This is called plagiarismplagiarism• It is one of the worst “crimes” in science• It will make you look bad, when discovered

(which will probably happen)• It may ruin your scientific career • Just don’t do it!

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Fraud in scienceFraud in science

• Publication of results you have not really acquired is considered fraud

• There are examples where “scientists” have published results that were copied from other journals

• Other “scientists” have published results that were not based on their experiments

• It is one of the worst “crimes” in science• You are bound to get caught: Just don’t do it!

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A final checkA final check

• Check the instructions for authors again

• Did you follow all instructions properly?

• Remember: it is not the task of it is not the task of the reviewers or the editorthe reviewers or the editor to take care of details you should have checked yourself

• Your manuscript may be sent back without review, if you have not addressed these items

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Before you submit your Before you submit your manuscript to a journalmanuscript to a journal

Ask a colleague, friend or a discussion group to “review” your manuscript

Their suggestions may lead to elimination of small mistakes and improve the

readability of your manuscript