Writing in science

Writing in science.

Report & Journal Articles

The Kenyon College Biology webpage was the source material for much of this tutorial.

Parts of a scientific paper.

Title Introduction Materials & Methods Results Discussion Acknowledgments (perhaps) References Appendices (for this paper)

General rules

You are NOT writing for the professor. Real scientists write for an audience who is smart, but who was not involved in the experiment.

Don’t refer to the work being done as part of a class, or to your group. Write as if you were a real scientist who did an experiment

Past tense everywhere: you already did the experiment

Rules of scientific writing

Headings (Introduction, Methods & Materials, etc.) at the top of each section.

Use precise language; avoid vague, uninformative terms.

The active voice should be used as much as possible.

General writing tips

Tell a story with a plot and make it interesting Plan how to order sections within the paper, paragraphs within the

section, and sentences within the paragraph Group all information about a topic together in a paragraph or

consecutive paragraphs. Don’t waste a sentence: “There are many kinds of college

students. They can be young, old, male…” should read, “College students can be young, old, male…”

Define jargon smoothly– Bad: “The humpback chub is endemic to Colorado. Endemic is defined

as a species that it occurs in one location but nowhere else.”– Better: “The humpback chub is endemic to Colorado, occurring there

but nowhere else.

General writing tips

Paragraphs start with topic sentence. Start each sentence with old information. Avoid “this, those, these.” Define new words; remind reader of previously defined

words not mentioned for a while. Join separate clauses with linking words: but,

therefore, etc. Conclude sentences with most important new thought. Use concluding thought of previous sentence to begin

next sentence.

Parts of a scientific report: the title

Self explanatory: casual reader should be able to tell what you did without reading the paper.

Bad Title: Human Genome Report

Better Title: An Investigation of Inheritance Patterns in the Family of Elsa Falls.

Best Title: An Investigation of Inheritance Patterns in Eye Color, Male-Pattern Baldness, and High Blood Pressure in Three Generations of Elsa Falls’ Family

Avoid excessively long titles

Titles should be self contained but not excessively detailed. This title has too much of a good thing:

“The effect of zero, five, and ten pound weights on the electromyograph of the extensor muscle of the human forearm, a study done as part of the Integrative Biology course at Randolph Macon College on twenty student volunteers during the week of February 7th in 2006.”

Purpose of introduction

Explains the reasoning behind your work.

Describes the context of your work and how it relates to existing work (such as providing new information to the field of study).

Clearly states the purpose of your work.

What are the basic things that you should ask before you write your introduction?

• What is the existing knowledge about this subject?

• Why did you undertake this study?

• What specifically were you going to do?

What is the existing state of knowledge about this topic?

You should synthesize information from the literature.

Should be an account that traces the development of knowledge on the problem and summarizes its current state.

The gaps and inadequacies of current knowledge should be identified.

Why did you undertake this study?

A good initial statement may be a description of an observation in nature.

A conclusion drawn from a survey from the literature that stimulated the your interest.

What specifically, were you going to do?

Indicate the specific objectives or testable hypothesis that will be considered.

These should be as specific as possible.

In the case of hypotheses: These should be statements that are clearly capable of being either supported or refuted by the work.

Structure of the Introduction

Follow a logical outline. One strategy that works well is the “funnel approach”

– Begin with a “global problem” statement that describes the large problem to which your work is related.

– End with a clear statement of the specific goal or goals of your specific work.

– Connect the two statements with a series of logical steps that describe the published information related to your work and build a logical case for the importance of your work

Additional Notes

Restrict background material to that which is directly pertinent to the problem.

An author of a scientific report should always be prepared to answer the question: Why did you include this material in the introduction?

Purpose of Methods & Materials

Allows replication of your work by others.

Allows others to assess the validity of your techniques and adequacy of your equipment.

Provides the sources of key equipment, reagents, & supplies.

Structure of Methods & Materials

Follow logical outline.

Use past tense.

Use genus and species name of experimental organism unless common (Human, Lab Mouse, Lab Rat)

Describe basic experimental design: number of treatments replicates and what are the controls.

Rationale for the methods

Structure of Methods & Materials cont.

Concentration and quantities of reagents used. Types and method of measurements made. Statistical test used and justification. In field studies, the description of study site and

location. Definition of new terms or abbreviations. Conditions of experiment: Temperature, light, pH,

etc.

Methods & Materials Do’s & Don’ts

Omit details that are not essential for the replication of the experiment by others.

e.g. I stuck the electrodes on my lab partners forearm but one fell off and we had to stick it on again.

e.g. Subjects lifted 10 lb weights bought at Jane’s Sporting Goods on Broad Street.

e.g. We wrote all the data down in our lab books so we could remember it later.


Use precise language.

Vague: We measured the electric discharge of the our fish several times during the study.

Precise: The frequency of the electric discharge of the Black Ghost fish was measured twice per day for three consecutive days.


Tell reader what was done using past tense rather than how to do it using present or future tense.

Incorrect: First , lower the electrodes in the aquarium. Then record the EOD for 1 sec. Afterward count the number of discharges in the voltage-time plot.

Correct: The frequency of the EOD was determined by counting the discharges on a 1 sec voltage-time plot of the amplified signal from the aquarium electrodes.

Purpose of Results

Concisely presents the data using text, graphs, figures, and tables.

Guides the reader through the data without interpretation so they can formulate their own opinion.

Structure of Results

Use concise and direct style that summarizes data in an objective and clear manner.

First sentence of each paragraph puts data in context or introduces aspects of data detailed in body of paragraph.

Body of the paragraph describes major tends or patterns illustrated by comparison between experimental groups and controls.

Refer parenthetically to each Table and Figure in paper.

Results Do’s and Don’ts

Avoid including all of the raw data in a table or figure or making all possible comparisons.

Usually means (averages) and a measure of variability such as the “standard error of the mean” are reported instead of raw data.

Use graphs and tables to supplement the text.

Figures

Pedigrees, graphs and other types of illustrative material are referred to as figures.

Graphs are used to illustrate trends in the data; include X and Y axis labels with units.

Numbered consecutively (Figure 1, 2, 3…).

Have caption at bottom stating source of data, type of variability measure (error bars), sample size, and statistics.

Figures

• Note number identifying figure.

• Note statement of figure contents.

• Note types of statistics.

• Note sample size provided.

• Note axes are labeled and units shown.

Figures

When to use a figure?

Use figure when you need to illustrate pattern or trend in data.

Use figure when data are too complex to summarize as a simple statement in text.

Figures

What type of figure to use?

Use bar graphs to illustrate data sorted in discrete categories eg. Types of E-fish

Use X-Y graph to illustrate continuous data, e.g. Frequency of electric discharge vs time.

Figures

What features should be included:

X-axis with label and units of independent variable.

Y-axis with label and units of dependent variable.

When means are graphed some indication of variation must be included: eg. “error bars.”

Figures

Error Bars

The mean, or some other measure of central tendency of the data, is often plotted in graphs along with the mean value plus and minus some measure of variability. This range, shown with a line, is called an “error bar.” The most common types of variability used in error bars are:

Standard Error of the Mean (S.E.M. or S.E.)

Standard Deviation (S.D.)

95% or 99% Confidence Limits or Confidence Interval (C.I).

Excel can calculate any of these from your raw data.

Figures

Bar Charts:

Note axes labels with units.

Note information in caption about what statistic is plotted and what the error bars indicate.

Note use of bar chart for categorical independent variable.

Note use of sans serif font (Helvetica) in chart.

Note ~ 2/3 proportion of height to width.

0

0.5

1

1.5

2

2.5

3

3.5

Masseter Bicep Tricep ForearmExtensor

Muscl

Max EMG output (mV)

Figure 9. The maximum EMG output of different muscle types under medium load (mean + S.E.M., n = 5).

Error bars

Masseter

BicepTricep

Forearm Extensor

0

0.5

1

1.5

2

2.5

3

Max EMG output

Muscl

Figures

What is wrong here?

Note lack of units for Y-axis Note lack of caption. Note lack of variability measure. Note gratuitous use of three

dimensional chart for two dimensional data.

Note unnecessary use of color (Only use color when it adds information!)

Note unpleasing proportion of height to width.

Tables

When to use a table?

Use a table when the data are not appropriate for a graph.

Use a table when the data can’t, usually because of complexity, be included in the text of the results.

Tables

Organization

Number each table separately from figures (Table 1, 2, 3…)

Caption goes above table. Organize data in columns to be read down. Include units in column names. Use footnotes to add explanation of columns if

needed.

Tables

MacIver et al., 2001

• Note table number and caption at top.• Note column format, column names, with units.• Note footnotes describing what values are.

Discussion: Purpose

The Discussion generally does two things:

1. it gives the “big lessons” that can be learned from the work

2. it compares the work to other similar research found in the literature.

Discussion: Do’s & Don’ts

The discussion is usually full of references

The discussion is not a summary

Emphasis should be on broadly applicable generalizations and principles

May use subheadings to separate major sections. (Only when necessary.)

End the discussion with a short summary of the significance of the work and conclusions drawn.

Discussion: Contents

Interpretations of the data.

Relate interpretations to the questions you posed in the introduction and the work of other researchers.

Clear up any discrepancies or ambiguities in your data or results. What further experiments might be performed to clear these up?

If necessary, make a new hypothesis that might be tested and that might explain why your results came out the way they did.

Discussion: Contents cont.

Did the results answer your question?

Did they support your hypothesis or not?

Draw some conclusions, supporting them with your data.

What is the significance of your results in the general area you studied?

What are the main principles demonstrated by your results?

Structure of the Discussion

Follow a logical outline.

Use a “reverse funnel approach”.

- Begin with specifics

- End globally

- Fill in between with connecting statements or paragraphs

The Refereed Literature

What it isn’t: Wikipedia and other encyclopedias, newspapers, magazines, web pages, lecture notes…

What it is– Scientific studies written by practicing scientists– Peer reviewed: 30-70% of papers are rejected by expert

reviewers who judge the information less-than-reliable– Expensive to produce: you won’t find it on Google– Published in “journals”

Finding Literature

Must have access to expensive databases– R-MC library pays thousands per database so

that you can search for free!

Link

Finding literature

Accessing databases in the Biology subject area:

Start with this one

Developing a Search Strategy

Learn to develop good search terms and to string them together appropriately:

Saving your references

View and select good articles, then email the citations to yourself. ILL to get full article

Formatting References

Next section after Acknowledgements Alphabetical order based on first author’s last

name. “Hanging” first line

Peterman, R.M. 1982. Model of salmon age structure and its use in preseason forecasting and studies of marine survival. Canadian Journal of Fisheries and Aquatic Sciences 39: 1444-1452.

Note: In MSWord, use “Format paragraph”, NOT tabs, spaces, returns, etc.


General format: – author(s), year, article title, journal name, volume,

pages.

Exact format depends on the journal if publishing or professor if turning in for grade.



Nit-picky rules are very important– No capitalization of article title.– No italics or underline (unless scientific name)– Pay attention to exact punctuation– Volume number, but not issue.


Citing References

Refer to all sources of information that you used in your paper.

All sources in a reference list must be cited in the paper and vice versa.

Cite: books, journal articles, etc. (Refereed or peer reviewed)

Sometimes: Cite any persons from whom you obtained information as “personal communication”

Additional information about citing references

Citation of a reference does not entitle you to “lift” passages of text.

Direct quotations must be set off by quotation marks.

Minimize exact quotations; extended quotes in science papers are rare!

Best to digest the information and present it in your own words.

Examples of Literature Citations

“The Loch Ness monster may be a big worm (Smith 1970).”

Smith (1970) thought that the Loch Ness monster might be a “big worm.”

Smith (1970) discovered that the Loch Ness monster is a huge worm-like creature.

Vagueness: Smith (1970) believed that the Loch Ness monster is wormy.

Johnson and Smith (1980) measured 1,000 skunks and found that they all stink.

More Examples

Radford et al. (2006) studied the Loch Ness monster and found that it was 10,000 years old.

The Loch Ness monster was 10,000 years old (Radford et al. 2006).

King (personal communication) graded my report too easily.

Elvis is not dead (King, B.,personal communication).

Literature Cited

Abbott, Thomas. 1999. The earth stands still when when professors speak. Journal of Irreproducible Results 50:1-5.Ashford, C.J. and Smith, O. 2004. Do professors know what they are talking about? Journal of Unacceptable Questions 101:20-30.Dodson, A.N., Knight, N., and Abbot, T. 1975. The response of number of dewberry leaf prickles to herbivory. Ecology 56:721-726.Isbell, Laura (in press). 2006. Diet selection by holly blue butterflies. American Journal of Botany.Mayberry, Xterra. 2004. Butterfly Identification Manual. Oxford Press, 120 pp.Jefferson, Thomas. 1995. The sex lives of dioecious hollies. Pp. 25 -45. In: Reproduction Strategies of Plants. McGraw-Hill, Inc., 560 pp.

Appendices

An appendix should be added to your paper where you will include all the family member information sheets for the 10 traits you initially investigated.

You must attach the first page of each reference you cite in your paper, arranged in the order of Literature Cited section.

Documents

Writing in science