A formal research article or less formal lab reports are the principal ways scientific data is conveyed to the rest of the scientific community and preserved for future examination. Each scientific journal has its own idiosyncrasies regarding particulars of the research article's format, but the most common elements of a scientific article, in order of presentation, are:
- List of Authors
- Materials and Methods
- Results, including figures and tables
The requirements for each section are outlined below. NOTE: This information is given in the order that you might actually write up your research, rather than the order in which the parts are presented in the final article. If you want more information, you can find parts of this text in an on-line collection of instructional materials used in the Purdue University Writing Lab (http://owl.english.purdue.edu). Other parts are inspired by Robert A. Day’s book, “How to Write and Publish a Scientific Paper” from Oryx Press, a copy of which can be borrowed from the teaching faculty.
It's also highly recommended that you read the article published in 2006 by the EMBO journal called Writing Readable Prose. It makes a strong case for the role that writing (good or bad) can play in your career development. It also makes explicit some elements of clear writing.
This is often the subject of many heated discussions and hurt feelings when only one report can be submitted to describe many people’s work. Since each of you will submit your own report, questions about who the authors will be, in what order, and what responsibilities each will have are moot. However you should list the name of your partner on your report since (s)he contributed to the work. Indicate that you are the primary author of the report by underlining your name.
Figures and tables
Some readers begin by scanning the figures first. The figures, with the legends, should provide a self-explanatory overview of your data. Decide what the data show, then create figures which highlight the most important points of your paper.
Tables are used to present repetitive data that is numerical. Graphs or illustrations, collectively called figures, are used to present numerical trends, raw data (like a picture of a gel), or a model that explains your work.
When you prepare your figures and tables, keep in mind that it is significantly more expensive for journals to publish figures and tables than text, so try to present the data in a way that is worthy of such added expense. The table below is an example of an ineffective table.
Temperature Repeats Cortical Cells Ion Flow
24°C 5 + +
24°C 5 - -
The information in Table 1 could be presented in one sentence, such as: “In ten experiments carried out at 24°C, ion flow was detected only in the presence of cortical cells.” This is a clearer and more concise way to present the information. In addition, all tables and figures must have numbers, titles and legends.
Figure and table legends
Legends to the figures and tables explain the elements that appear in the illustration. Conclusions about the data are NOT included in the legends. As you write your first draft, state in a short simple sentence, what the point of the figure or table is. In later drafts, make sure each element of the figure or table is explained. Your figure legends should be written in the present tense since you are explaining elements that still exist at the time that you are writing the paper.
The purpose of the results section is to present your data in a relatively unbiased way, but with some guiding framework. Begin with a short description of the goal and strategy of your overall experiment, and then delve into specific sub-sections that describe each piece of the work. Titled sub-sections help support your high-level narrative and make dense papers easier to read.
To write the results section, use the figures and tables as a guide. Start by outlining, in point form, what you found, going slowly through each part of the figures. Then take the points and group them into paragraphs, and finally order the points within each paragraph. Present the data as fully as possible, including stuff that at the moment does not quite make sense.
Verbs in the results section are usually in the past tense. Only established scientific knowledge is written about in the present tense, “the world is round,” for example. You cannot presume that your own data are part of the body of established scientific knowledge, and so when you describe your own results, use the past tense, “a band of 1.3 kb was seen,” for example. There are, however, exceptions to this general rule. It is acceptable to say, “Table 3 shows the sizes of the DNA fragments in our preparation.” It is also acceptable to say, “In a 1991 paper, Ebright and coworkers used PCR to mutagenize DNA.”
Materials and methods
This section is like a cooking recipe and should provide enough detail to allow an independent investigator to repeat any of your experiments. It's common (and helpful!) to include sub-section headings to allow readers to quickly identify experiments of interest to them.
The Materials and Methods section should be written in the past tense, since your experiments are completed at the time you are writing your paper. It should also be written in complete sentences and paragraphs, not in bullet point form. Finally, be sure to cite the class wiki at the beginning of this section as follows: "Protocols were according to the 20.109 Fall 2010 lab wiki: URL accessed on January 1, 2020, unless otherwise noted."
This is the section of the paper for you to show off your understanding of the data. You should begin by reiterating the purpose of your research and your major findings. Then you can go to town: you might try connecting your findings to other research (published or that of your peers). You might describe any ambiguities and sources of error in the data. You might describe any conceptual or technical limitations of the research. You might suggest future experiments to resolve uncertainties. You might explain where you expect your work may lead. And you might suggest specific experiments for extending your findings. Finally, you should explain the significance of your findings to basic science and to engineering applications. Like the previous sections, the discussion should have a clear organization and narrative flow, whether or not you use sub-sections.
Introduce what your question is. Explain why someone should find this interesting. Many of the most readable introductions do a great job of first summarizing what is currently known about a topic and then justify the work by identifying a gap in understanding that the authors will address. If you've set up your introduction this way, then after identifying a gap or a need to justify your project, then you can introduce a little of what you found and how you found it. You should explain any ideas or techniques that are necessary for someone to understand your results section. Remember that the goal of this section is two fold: first, you must provide sufficient background information for a reader to understand the forthcoming results. Second, you must motivate the audience to keep reading by hooking them with connections to prior research and interesting future applications.
Most introductions are "funnel" shaped in terms of content:
- Opening paragraph(s): most general, "big picture" paragraphs. This is the place to introduce the reader to the broader context of your experiment and motivate why your research is important. The best introductions tell a coherent story, not a dense but unconnected list of facts. Identify a gap in understanding or a need that your work will address.
- Middle of Introduction: "zooming in" somewhat. Once the reader has a frame for thinking about your research, you can present background information in more depth.
- Wrapping up: most specific, a description of your particular investigation.
The abstract is a very short summary (not >250 words) of your report, including what the question is, what you found, and why it may be important. By convention, it should be single-spaced and not include citations.
The importance of a good abstract cannot be overstated since computers generally index the words in a paper’s title and abstract, and thus these may be the only parts that many people read. The abstract may also be the way a journal’s editor decides whether to send your paper out for peer review or reject it as uninteresting and not generally relevant.
The title should be short (about 10 words), interesting, and it should describe what you found. Avoid very broad titles (e.g., 'DNA recombination'), and try to specify your own unique result within the limited space, while still maintaining readability of your title.
See MIT libraries information on citing sources, here. In your report, you should include only those references that pertain to the question at hand. To illustrate the relevance of the articles you cite, you are asked to annotate half of them. Your annotations need only be 1-2 sentences long and they state the relevant point of the article that you have included. A nice example of an annotated reference list can be found here.
Journals vary considerably in their preferred format for the reference list. For this class, you should list the references alphabetically by the first author’s last name. Include all the authors, the paper’s title, the name of the journal in which it was published, its year of publication, the volume number, and page numbers. Please carefully follow the punctuation and format requirements. A typical reference should look like
Pavletich NP, Pabo CO. Zinc finger-DNA recognition: crystal structure of a Zif268-DNA complex at 2.1 A. Science 1991; 252:809-817
In the body of your report, this article would be cited as follows:
“The crystal structure of the Zif268-DNA complex has been solved (Pavletich 1991).”
If two or more articles can be cited for this finding, then they are listed alphabetically, separated by a comma.
Scientific Writing 101
Again, it's worth reading Writing Readable Prose.
Lesson 1: Structure and Repetition
The readability of your paper can be substantially improved by its organization. Well chosen sub-section titles provide the reader with a distillation of the high-level points you want to make. Take the opportunity early and often to summarize major points - if you do this right, you will feel like you are repeating yourself too much! Each major section of the report should be more or less stand-alone, that is, understandable without having read the rest of your paper. Be sure and work from big to small to big (from broad points to details and back) throughout your paper. Finally, limit paragraphs to one topic apiece, splitting up longer linked ideas as needed.
Lesson 2: Results vs. Discussion
One difficult task for budding scientific writers is determining what goes in a Results vs. a Discussion section. Even at the professional level, different scientific journals may have somewhat different expectations for how much interpretation is appropriate in the Results. A good rule of thumb in most contexts is to draw technical conclusions in the Results, but save scientific conclusions for the Discussion. An alternative framework that should yield similar writing choices is to focus on relatively certain conclusions in the Results, and save more speculative (but still supported!) conclusions for the Discussion.
Example of a technical conclusion: "Sequence alignment revealed that both mutants exhibited mutations in at least one of the expected sites and thus were consistent with the possible nucleotide changes that could occur with the library used."
Example of a scientific conclusion: "A previously reported model proposes that the OmpR-P phosphatase reaction occurs by hydrolysis rather than direct phosphotransfer from H557 (Hsing 1997). Our mutant is consistent with a change to the structure of EnvZ that facilitates this hydrolysis reaction, thus increasing phosphatase activity while concurrently reducing kinase activity."
Lesson 3: Holistic View of Data
What should you do when two independent pieces of data suggest two very different conclusions about your overall experiment? The one thing you should not do is state that both conclusions are correct, in different parts of the paper, and hope that the reader will ignore the discrepancy! As a scientist, you must take a holistic view in your analyses. Is there any way to reconcile the two results? Is one method more trustworthy than the other or is there otherwise an indication to favour one conclusion over the other? If you have no way of determining which result is correct with your present data, can you propose future experiments to conclusively decide?
Lesson 4: Concision
Writing concisely takes more effort than writing inefficient prose. It is also results in eminently more readable text that expresses your ideas more powerfully.
Lesson 5: Precision and Detail
Being concise is not an invitation to being vague. Be sure to support your claims with specific examples, and to follow through on your ideas with sufficient detail.
Lesson 6: Writing Is Revision
The first draft is a record of your ideas; the second draft is a crafted presentation of them. Draft as much of your report as possible early on, so you have the opportunity to revise it before submission.
The following table describes the features of reports that are excellent, good, and that need substantial improvement, respectively from left to right. Your own reports will be evaluated with these features in mind.
||To give content information to reader
- Not enough content information or too much
||To concisely summarize the experimental question, general methods, major findings, and implications of the experiments in relation to what is known or expected.
- Key information is presented completely and in a clear, concise way
- All information is correct
- Organization is logical
- Captures any reader’s interest
- Sufficient information is presented in proper format
- Would benefit from some reorganization
- Understandable with some prior knowledge of experiment
- Some key information is omitted or tangential information is included
- Some information is misrepresented
- Some implications are omitted
- Incorrect format is used
||To identify central experimental questions, and appropriate background information. To present a plausible hypothesis and a means of testing it.
- Relevant background information is presented in balanced, engaging way
- Your experimental goals and predictions are clear and seem a logical extension of existing knowledge
- Writing is easy to read
- All background information is correctly referenced
- Relevant background information is presented but could benefit from reorganization
- Your experiment is well described and a plausible hypothesis is given
- With some effort, reader can connect your experiments to background information
- Writing is understandable
- Background information is correctly referenced
- Background information is too general, too specific, missing and/or misrepresented
- Experimental question is incorrectly or not identified
- No plausible hypothesis is given
- Writing style is not clear, correct or concise
- References are not given or properly formatted
|Materials & Methods
||To describe procedures correctly, clearly, and succinctly. Included a correctly formatted citation of the lab manual.
- Sufficient for another researcher to repeat your experiment
- Lab manual cited
- Procedures could be pieced together with some effort
- Lab manual cited
- Procedures incorrectly or unclearly described or omitted
- Lab manual not cited
||To present your data using text AND figures/tables.
- Text tells story of your major findings in logical and engaging way
- Figures and tables are formatted for maximum clarity and ease of interpretation
- All figures and tables have numbers, titles and legends that are easy for the reader to follow
- Text presents data but could benefit from reorganization or editing to make story easier for reader
- Text includes interpretation of results that is better suited for discussion section
- Figures and tables are formatted to be clear and interpretable
- All figures and tables have numbers, titles and legends
- Text omits key findings, inaccurately describes data, or includes irrelevant information
- Text difficult to read due to style or mechanics of writing
- Text difficult to read due to logic or organization
- Figures and tables missing information, improperly formatted or poorly designed
- Figures and tables have inadequate or missing titles or legends
||To evaluate meaning and importance of major findings
- Appropriate conclusions drawn from findings
- Connections made between experimental findings
- Connections made between findings and background information
- Future directions considered
- Writing is compelling
- Appropriate conclusions drawn from findings
- Experimental limitations considered
- Writing is clear
- Conclusions omitted, incorrectly drawn or not related to hypothesis.
- Relationship between experimental findings and background information is missing or incorrectly drawn
- Writing style and mechanics make argument difficult to follow
||To give credit work on which your own is based
- Complete list of reliable sources, including peer-reviewed journal article(s)
- Properly formatted in body of report and in reference section
- Annotations clear and correct
- Adequate list or reliable sources
- With minor exceptions, properly formatted in body of report and in reference section
- Most annotations clear and correct
- List is incomplete or includes sources not cited in body of report
- List includes inappropriate sources
- List not properly formatted
- References not properly cited in body of report
- Lacking annotations
|Writing Style and Mechanics
- Appropriate for audience
- Consistent passive or active voice
- Too simple or too advanced
- Irregular use of passive and active voice
- Says what you mean
- Scientific vocabulary used correctly
- Ambiguous or incorrect
- Scientific vocabulary misused
- Sentences and paragraphs well structured
- Punctuation correct or only minor errors
- Grammar correct or minor errors
- Spelling correct
- Sentences repetitive or awkward
- Paragraphs not logical
- Periods, commas, colons and semicolons misused.
- Significant number of run-on sentences, sentence fragments, misplaced modifiers, subject/verb disagreements
- Significant number of spelling errors
- Past tense for describing new findings
- Present tense used for accepted scientific knowledge and figure legends.
- All sections included and properly formatted
- Misleading verb tenses
- Some sections missing
- Abstract not single spaced
- Figures missing legends
- References not properly formatted