Writing in the Natural Sciences

by Tara Porter, WAC Fellow



v     Introduction

v     Types of Scientific Writing

Scientific Papers

Some Guidelines for Writing Lab Reports

Grant Proposals

Review Articles


v     Common Style Issues



v     Avoiding Plagiarism

Citation Methods

Using Your Own Words

Using Accurate Sources

v     Structure

Some Faculty Tips on Structure

v     Additional Advice From CSUS Instructors

This guide includes information from Karen Jackson's "Writing in the Natural Sciences" found at http://www.csus.edu/wac/science.html.


"The ability to write clearly is critical for high performance in science courses. Everything from essay exam answers to lab write-ups require solid written communication. If the student's understanding of a concept doesn't come across clearly in their exams or papers, then their assessment may reflect a misunderstanding. In other words, if the student "gets it" conceptually but can't effectively put it into writing, they might not get credit for "getting it"

(Dr. Nathan Trueblood, Biology Department, CSUS).

The scientific world consists of chemical equations, lab procedures, detailed measurements, graphs, and many more "elements."  But the hidden, although vastly significant, side of science is the writing: grant proposals, lab results, and research articles.  Writing becomes the medium by which a scientist translates his/her work.  The clarity of the writing reflects on the performance of the scientific research. If a scientist is unable to relay results and theories with clarity, the scientific community is left with little understanding of the research conducted.

In the classroom environment, writing holds the same value.  CSUS Biology Professor Amanda Enstrom stated that, "The ability to effectively communicate ideas, especially scientific ones, directly impacts not only the evaluation of the student's progress but could also be an asset or a hindrance to the student in the workforce. When grading, I consider the clarity, succinctness, as well as individual perspective/opinion of the writing. ‘A' papers are those in which the student conveys an understanding of complex biological systems in his or her unique perspective rather than just regurgitation of printed material" (Professor Enstrom, Biology Department, CSUS)." Good scientific writing communicates with the reader and therefore serves as a medium between the scientific findings and the audience.

This guide will help improve your writing in the Scientific Field. We will discuss various types of scientific writing, as well as different stylistic features of the academic field.  We will also review tips and guidelines on scientific writing that were provided by CSUS Professors in the Natural Sciences.

Types of Scientific Writing

Most scientific writing can be divided into four categories: Scientific Papers, Grant proposals, Review Articles, and Posters. All four of these types of writing serve a different purpose. Scientific papers serve as a detailed account of a research project. A Grant Proposal provides a summary of proposed research and is generally sent to a funding agency with the hope of financial support.  Review articles provide an overview of current advances in a particular scientific field.  Posters allow researchers to present their research to large audiences in a short amount of time.

Scientific Papers

Scientific papers provide the community (either scientific or public) with a detailed understanding of the various steps you took to carry out your research. These "steps" not only include the specific steps you went through to conduct your research, but also include background information, hypotheses, and results, to name a few.

The following section, "Some Guidelines for Writing Lab Reports", is provided by Dr. Brad Baker from the Chemistry Department at CSUS.

Some guidelines for writing lab reports

Reports should be no longer than they need to be to completely describe the work that was done and meaningfully explain the data that was obtained.  Remember, your work in the lab is as good or bad as your lab report. 

The following is not necessarily a complete guide for report writing, but just some suggestions that I have thought of and written down while reading a variety of students' lab reports. 


A proper abstract is a concise summary of the paper (or presentation, or book chapter).  It is not an introduction.  The abstract should include a brief introduction to the experiment, why it is important, how it was carried out, and the important results that were obtained; including important numerical data.  The amount of detail given in the abstract will depend on the allowed length.

An abstract needs to stand on its own.  In general, references to other works should not be included unless there is a compelling reason to include them.  References to figures and tables that may appear in the main body of the paper should not be made.  Figures and tables may be included in extended abstracts, which are usually unless they refer to written for conference proceedings.  If acronyms are used they must be defined the first time they are used. However, since the abstract stands alone, acronyms must be defined again in the main body of the paper, even if they have already been defined in the abstract.  Do not use an acronym if it is not going to be used again.


          The introduction is used to tell the reader why you did the experiment. The introduction should include a discussion of the science behind your experiment, and results that others may have attained.  Important historical references regarding work related to your experiment should be in this section.  If your experiment tested a particular hypothesis or theory, it should be stated in the introduction.  The results of your experiment should not be given in the introduction.  There are usually no figures or tables in the introduction, unless they are referenced from some other source.

Parts of the introduction may be in the past tense and others in the present tense.  If you are discussing a specific experiment or specific work that happened in the past, it should be presented in the past tense or mixed tense.  For example, "Smith et al. (2003) found that time of flight mass spectroscopy works better than ion trap mass spectroscopy due to the faster response time."  If you are discussing something in general that is not linked to a specific reference, use the present tense.  For example, "Isoprene is the most prevalent volatile organic compound emitted by plants."  A statement like this may be followed by one or more references if it is not general knowledge in the field.


          The experiment section tells the reader how you carried out your work. This section should describe in detail:  where chemicals were obtained and what quality they were, methods and equipment used, any parameters that were set for these methods or equipment, how instrumentation was calibrated, how experimental controls were set up, any sampling and analysis protocols that were used, calculations that are not routine, etc. The amount of detail given should not be more than is necessary for the reader to repeat what you have done in the general sense.  For instance, if you are describing how calibration solutions were made, it is appropriate to say, "A range of Ca2+ calibration solutions from 1.00µM to 10.0µM were prepared using volumetric glassware by serially diluting the 5.00mM Ca2+ stock solution with deionized water."  (We assume here that the 5.00mM Ca2+ stock solution has already been discussed.)  This amount of detail will allow anyone familiar with wet chemistry to make calibration solutions in the proper range.  It would not be appropriate to say, "To make a 10µM Ca2+ calibration standard, 2.00mL of the 5.00mM Ca2+ stock solution was added to a 1000mL volumetric flask using a 2.000 mL volumetric pipet, and then the volumetric flask was diluted to the mark with deionized water."  This statement is wordy and unnecessary.  However, if you are discussing a procedure that is new, extremely uncommon, or very sensitive to small changes in the procedure that may alter the outcome of the experiment, then this sort of detail may be appropriate.  If some parameter was changed half-way through the experiment (and data is used from both before and after changing the parameter), then it should be mentioned in the experiment section. Why the parameter was changed should appear in the discussion section (a brief comment on why it was changed could be included in the experiment section to avoid confusion).  None of your actual data or results should be presented in the experimental section.

Figures may be used in the experimental section if they show how an instrument was set-up or to show visually how an experiment was carried out.  A table may be used to demonstrate a sampling protocol in a better way than could be explained in the text.  In general, figures and tables should always be used sparingly, and only if they result in a better presentation of information than can be accomplished in the text.  Never put a figure or table in your paper unless you refer to it in the text, and specifically discuss the contents of the figure or table in the text.  If one of your figures is used to show an equation, use an equation editor to properly present this.

          Most of the time, the experimental section will be written in the past tense.  Any time you discuss something that was done in your experiment it should be in the past tense.  However, if you are writing about something in the general sense, then the present tense should be used.  For example, "Mass 67+ was used to monitor isoprene since it is the most prevalent mass produced in the electron impact ionization of isoprene."  The first part of the sentence is in the past tense since it refers to the experiment, the second part of the sentence is in the present tense, since it is a general property of electron impact ionization.


          The results/data section presents your data to the reader, but does not present an analysis of that data.  Since this is sometimes difficult to do, it is common to combine the results section with the discussion section.  Only show results that are pertinent to your experiment.  If you made a mistake during the experiment, do not show the data from the mistake.  Only show bad data if that data was used to direct the next step of the experiment.  This would be common if your experiment involved method or instrument development.  Do not show the same type of data more than once unless there is a good reason to do so.  If you are analyzing ten samples with various concentrations of phenols by chromatography there is no reason to present more than one of the chromatograms; in general, they all look the same.  A graph of concentration versus sample number, or time, or whatever is appropriate, would be more useful to the reader.  Be sure to always use the appropriate number of significant figures in every number you report, including on the axes of graphs.  Also be sure to include units with every number you report in the text, and in figures and tables.  If the units require superscripts or subscripts, format these properly.  There is no excuse not to use superscripts or subscripts when using a modern word processor.  Avoid reporting raw data.  For example, if you want to show the results of several chromatography analyses in a table, convert the area units to concentration (based on the calibration), or some other useful units before making the table.  An exception to this may be if you are reporting the results of repeated standard analyses to demonstrate precision. 


          The discussion section should be used to put your results into the proper context.  It is commonly combined with the results section.  The results of the experiment should be explained in a meaningful way.  This may include:  comparing your results with the results of others (in your class or from published work), comparing various results from your own experiment, explaining how your work demonstrates a certain scientific principle, or supports or disagrees with a particular hypothesis or theory, discussing the quality of your data and if the quality of the data is not as good as possible, why, etc.  If you want to show the process of making specific calculations, put these in an appendix at the end of the report.  Do not go through detailed calculations in the main body of the report; although important equations that are used for making calculations may show up in the experiment section.  Detailed calculations should only appear in the main report if the study involves the derivation of the equations.  The discussion section of your report should be the most thought out and interesting.


          An effective conclusion is used to reflect on the experiment, to suggest improvements for future experimenters who might repeat the work, and to suggest ideas for further studies that the current work has inspired.  The intention of the experiment may be repeated (from the introduction) and whether or not the original goals were met can be discussed.  Although the major results may be restated in a conclusion, this is not the primary purpose of this section.

Helpful comments on figures and tables

-Only use a figure or table when necessary.  Ask yourself if the information in the figure or table can be adequately described in the text alone.

-Label figures and tables separately and in order.

-A caption should be associated with every figure or table.  The caption should not rely on the text of the paper, although the reader can be referred to the text for more information.

-Every figure and table included in the paper must be referred to in the text, and must be referred to in order.  If the figures and tables are embedded in the text, try to have the referral in the text come before the figure or table appears.  Otherwise, it is acceptable for all of the figures and tables to be included (in order) at the end of the text.

-The first time that the figure or table is referred to in the text, the figure or table must be described.  Describe what the figure or table is displaying, and then discuss the data in the figure or table.  After this, it is ok to make a reference to the figure or table without a specific discussion of the data in the figure or table.  Use the present tense when referring to the actual table or figure.  For example, "Figure 1 illustrates how the helium carrier gas was used to desorb compounds from the sampling traps."

-Use the correct or at least a reasonable number of significant figures in every number reported (and be consistent).

-Whenever possible, show uncertainty in your data.  Use error bars on graphs to show uncertainty in each point, or to show variations from one analysis to the next.  Be sure to explain your error bars or uncertainty in the caption.

-Units must be associated with every number reported.  This may appear in the column heading for a table, or on the axis label in a graph.  For chromatograms it is ok to use ‘detector response' for the units of the y-axis, and area units for peak areas, however it is better if area units are converted to the final units used (the same units as the standards).

-Most instrument software allows the user to format how data looks for printing.  Spend the time to learn the software and make your data look the way you want before printing it out.

-The font for all lettering should be the same as in the text whenever possible.  Do not use smaller than 10 point font in figures and 12 point in tables.

-All lines and points should show up clearly.  This includes axis, trend lines, and data points.

-Use all of your space.  There is no reason to have a graph on half a piece of paper if the other half is empty.

-Use enough space to display the data well.  Short and wide chromatograms do not do as well as tall ones.

Some unacceptable errors commonly found in lab reports

-Having numerous and blatantly misspelled words.

-Using poor writing structure (not having periods after sentences, missing spaces, etc.).

-Not describing and discussing figures and tables that are included in the report.

-Poor labeling of figures and tables, for example, if multiple figures have the same figure number, or if the incorrect figure is given in the text.

-Being excessively redundant.  Never repeat what you have already said in the report; especially word for word.  It may be appropriate to restate an idea if it is very important.

-Not reporting units (or incorrect units) and obviously reporting too many significant figures.

-Not using appropriate symbols, sub, and super scripts, and not using an equation editor to display equations.

All of these can easily be avoided by carefully reading your report before handing it in and having some pride in your work.

Grant Proposals


Grant Proposals are usually submitted to government organizations. In these proposals, you argue that a particular experiment you plan to run contributes significantly to the science community. Based on whether or not the granting agency finds your proposal compelling, you may receive funding to conduct research.


Note: Grant Proposals generally need to go through the University before you send it off to the government agency.  Make sure you discuss your plans with your department and become acquainted with university policies and procedures.


The main thing to remember when writing a grant proposal is to be clear in what you write. Constantly anticipate what problems the granting agency would have with your study and justify those issues.


As far as format is concerned, consult the granting agency for format specifications.


Review Articles

Review articles are often included in journals and provided a great overview of current advancements in a certain field.


Reviewers generally describe what is currently developing and what is left to be answered for a particular topic.  These reviews are read by researchers in related field.   A researcher could use the review articles to gain a grasp of recent developments on a particular topic. Because many researchers consult these for a briefing, it is important to keep the language slightly less complicated than you would in an actual research report.


Quick Tips for Review Articles


Review articles are frequently written by one author.


Keep out the bias—journals do not typically look for biased reviews.


Keep out quotations; instead, give a brief overview of what the researchers found


This differs greatly from book reviews and film reviews, where the writer is at liberty to rip the work to shreds. Instead, your responsibility is to provide a clear overview (however, sometimes you might point out limitations – just make sure you watch your tone).


Instead of discussing one article after another, make sure you discuss the overall topic and briefly incorporate those articles into your discussion.


Use present tense to discuss your summary of the findings, but use past tense to describe what the researchers found out on the individual studies.


Gain a good grasp of what is out there.  What are the major reports on this topic? (one key way to figure this out is to look at the works cited page of the article your are reviewing) Where is the research currently standing on this topic? What is left to be researched? Have there been any recent conferences where research on this topic has been discussed? www.pubmed.com is a great source for finding scientific articles-just enter in the key words of your topic and look through the abstracts.


Order of Review

  1. Discuss why the topic is important.

  2. Divide these sections by the different topics you researched, do not organize it according to each research article you studied. Make these paragraphs unique by immediately drawing in the reader and identifying the main similarity or difference you found on that topic.

  3. Discuss what is currently known on that topic and what questions are left to be answered.

(This is a summary of a timeline offered by Penrose and Katz (2004). For more detailed information, see p. 84 of Writing in the Sciences).


Posters provide you with an opportunity to get a large audience to quickly review your research. The poster should contain your abstract, major findings, graphs, figures, and final conclusions. Be sure to also include a list of references.  The majority of posters are pulled from sections in your research project. Many departments have printers that print large-sized posters and laminate them.

Posters will generally be displayed at conferences. You will most likely stand with your poster and provide audiences with a brief summary of your research and answer any questions.

   Common Style Issues

"Even if I don't grade explicitly on quality of writing, a well-written answer allows a student to express their thoughts fully and for me, the reader, to understand those thoughts. Poorly written work is confusing and difficult to read.  As a reader, and grader, I might not appreciate how much a student knows about a topic, or
the depth of that knowledge, if an answer is poorly written."

(Dr. Ron Coleman, Biology Department, CSUS)


The two common style issues found in scientific writing are Voice and Tone. As indicated by Dr. Coleman's statement above, well-written papers impress the scientific audience.  Both Voice and Tone are writing features that could enhance the quality of a scientific paper.



Passive sentences are associated with science writing because of the goal of objectivity.  Science tries to remove the experimenter from the experiment as much as possible, so the use of first person has traditionally been avoided, leading to a predominance of passive sentences.  So we see lots of writing like, "The samples were collected," versus "The experimenters collected the samples," or "We collected the samples."  (Jackson)


Passive Voice

The sample was tested and revealed no traces of bacteria.

Without Passive Voice

We tested the sample and found no traces of bacteria.

Although passive voice is usually used, more and more publications want an increase in the use of active voice.  This debate is one demonstration of the constant advancement of the scientific field, not just in the form of scientific findings, but in the language itself.

Argument Supporting Active Voice

Although there might be circumstances that require the use of passive voice, you might express your views more clearly without it. 

"It is perfectly acceptable to use the pronoun ‘I' in scientific writing; switching to the active voice expresses thoughts more forcibly and clearly and often eliminates unnecessary words" (Pechenik 98)


Argument Supporting Passive Voice

"In some cases this preference for third person is changing as scientists acknowledge the unavoidability of observational effects.  The simple act of observing changes the object being observed.  However, the use of first person should only occur under the advice of your professor or the instruction of journal editors.  Third person remains the safest bet unless directed otherwise.  Please don't think this is a discouragement of active sentences, however.  Use the active voice as often as possible, but passive sentences cannot be avoided when you use third person to describe an experiment." (Jackson)


"Scientific papers and lab reports are also written in present tense for the most part. There are only two possible exceptions to this rule.  The first is the Methods section as you describe the steps you have already performed in your experiment.  You're most likely to see this section in the past-tense, but other teachers prefer you to use the imperative, or commands, as was written in your lab manual.  The only other exception is the Introduction or Background section of a scientific paper where previous experiments are summarized.  As you are talking about something done in the past, use past tense here.  (Jackson)

   Avoiding Plagiarism

Since a large portion of scientific writing involves discussing previous research studies, it is important to understand the rules against plagiarism to maintain your own academic integrity.


Citation Methods

"The main problem with students is understanding what is appropriate paraphrasing and citation and what borders on plagiarism"

(Dr. Amanda Enstrom, Biology, CSUS).

For in-text citations, you would either use a citation sequence (using numbered footnotes that are in order of appearance at the end of your essay) or include the name and year of the study. Check with your professor or journal to determine which format is expected of you.  For examples of these citation methods, please consult the following websites:

Number System:


Name System:


Using Your Own Words

"The biggest problem that my students have is being able to put their references into their own words. Plagiarism is really the number one problem in my classes and most of it is accidental. The other problem that I have is when students do not cite references properly in the format that is assigned to them, many just want to use MLA and leave it at that."

(Dr. Keely Carroll, Biology Department, CSUS)


Using Accurate Sources

"Excessive reliance on dubious sources from the internet can be problematic. Taking advantage of library instructional resources can address this problem as well as holding
students to a high standard" (Dr. Winston Lancaster, Biology Department, CSUS).


One important thing to remember when writing in the sciences is remembering to be flexible. Depending on what journal, professor, supervisor, or grant-issuing agency you are writing to, you will have to alter your writing.

Be sure to confirm what structure and style is required of you.

Some Faculty Tips on Structure

"Another problem students seem to have immense trouble with is the structure of their papers. I do feel it is important for instructors to convey to undergraduate students the utility of first writing an outline and to upper division and graduate students the common structures most journal articles are in. At that level, students writings should reflect peer-reviewed journal articles and review articles as closely as possible, as this will ease their transition into a scientific career"

( Professor Ernstrom, Biology Department, CSUS).

"Read scientific writing critically to see how it is structured and then strive to write that way.  Notice the subtleties of tense, e.g., the Introduction of a scientific paper is often in present tense while the Methods are often in past tense.  Paragraph structure is vital, etc. Most importantly, notice how good writing is a pleasure to read and aim to provide that pleasure to your readers"

(Dr. Ron Coleman, Biology Department, CSUS).


   Additional Advice From CSUS Instructors

If CSUS Science Professors had one piece of advice to give you, what would they say?

"Plan what you are going to write before writing anything! The
effectiveness of the writing is greatly diminished if the paragraphs are
poorly structured. Also, to avoid plagiarism and ease finding citations,
write the main research finding on a post-it note and affix it to the
journal article. It will assist you in finding the correct citation and will eliminate
any temptation of copying verbatim"

(Professor Enstrom, Biology Department, CSUS).

"Organize and give scrupulous attention to the citation of sources"

(Dr. Winston Lancaster, Biology Department, CSUS).

"Practice your writing and read it out loud to yourself to see if it makes sense to you. Try to replicate your experiment using your methods and materials section to see if you were complete enough and look for where you might need references. Also, keep in mind that the internet is not the only source of material out there"

(Dr. Keely Carroll, Biology Department, CSUS).


"Outline, write, revise, revise, revise...."

Dr. Nathan Trueblood, Biology Department, CSUS