Is writing important in chemistry? Don’t chemists spend their time turning knobs, mixing reagents, and collecting data? They still get to do those things, but professional scientists also make presentations, prepare reports, publish results, and submit proposals. Each of these activities involves writing. If you remain skeptical about the need for writing skills, then ask your favorite professor, or any other scientist, to track the fraction of one workday spent using their word processing program. You (and they) may be surprised at the answer
Although the exchange of information in science usually focuses on content rather than writing style, it is important that work be presented using accepted conventions and in an appropriate syle. Whether your audience consists of readers, reviewers, seminar attendees, or the boss, a clear, concise writing style can help to gain their confidence, maintain their interest, and convince them of your work’s value. In a competitive environment, this can be an important part of having your manuscript accepted, getting your grants funded, or even getting your well-deserved promotion.
This guide is meant to give a short introduction to writing for chemistry students at Oregon State. It is not a comprehensive writing reference, and most likely will not address specific questions that arise. It will introduce some major issues in writing about chemistry, and point you to some excellent resources. Since chemistry students will spend most writing time producing lab reports, that will be one focus of this guide.
Resources for help with writing
It may seem obvious, but remember that your instructors are there to help. Did they provide handouts or online information with specific instructions on style, format, and a checklist of items to include in the report? Since expectations will vary from class to class, and sometimes even from report to report, it is important to understand what is being requested before organizing your results and beginning to write. A grading sheet specifying the number of points or relative weight given to each part of the report can help you to focus your efforts. Find out if your instructor will provide these in advance.
The ACS Style Guide, A Manual for Authors and Editors, 2nd ed. (Dodd, J., Ed.; American Chemical Society, Washington, DC, 1997) is an excellent resource with writing tips and detailed descriptions of the ACS writing conventions. This is also a required text for the chemistry writing intensive (WIC) classes CH 462 and CH 463. We strongly suggest that you invest some money in this reference as soon as you begin the integrated lab sequence. The guide can be ordered at http://www.oup.com/us/catalog/J778/?view=usa
The OSU Student Writing Center in 123 Waldo. (tel. 737-5640; http://oregonstate.edu/dept/writing-center/) provides free writing assistance to OSU students. That could be the best deal on campus ! Their services include one-on-one appointments to discuss your individual writing projects and questions, an on-line form for submitting work in progress for critical evaluation, and an e-mail address (WritingQ@mail.orst.edu) where specific questions about sentence mechanics, punctuation, documentation, and style are promptly answered.
Some handy online resources.
As noted above, instructors differ in their expectations for lab reports. This is reasonable when you consider that there is also a wide variation in the requirements for different chemistry journals and publishers. Even so, a long experience in reading lab reports, papers, and thesis drafts indicates that there are common areas of confusion for many students, and therefore we provide a few general guidelines to help in creating reports or publications.General guidelines for writing reports
1. Use the correct verb tense
Lab reports and research papers should be mainly written in the present tense. You should limit the use of the past tense to (1) describing specific experimental methods and observations, and (2) citing results published in the past. The following sentences can be written in the past tense:
The solid was washed with water, then dried overnight in a dessicator.Jones et al found that polymers with absorption maxima between 200 and 300 nm degraded when exposed to ultraviolet radiation.
Data analyses, on the other hand, should be written in the present tense:
Extrapolation of the line in Figure 3a gives a polymer viscosity of 40.2 cp: an error estimate using eq. 2 provides an uncertainty of 0.4 cp.
2. Write in the third person
A common question is whether the words I, me, my, we, our, or us, belong in science writing. Because scientific experiments demonstrate facts that do not depend on the observer, reports should avoid using the first and second person. For example, the second sentence below is better because it avoids the use of the first person:
Stirring the solution for 2 h, and subsequent filtration, yielded a yellow powder.
However, when referring to your own results or conclusions, it can be simpler and clearer to use the first or second person:
While Smith and Jones report a cell dimension, c, of 23.3(1)Å, the authors' own data indicate a value of 23.6(1) Å.Smith and Jones report a cell dimension, c, of 23.2(1) Å, but our data yield a value of 23.6(1) Å.
The authors' own data is an awkward phrase and "our data" in the latter sentence is better.
3. Be clear but concise
Reports and papers should fully describe experiments in a precise and factual manner. Both the depth of the error analysis and the writing style must be appropriate to this task. Consider the following sentence in a discussion:
The calorimeter vibrated a little, but it is still easy to measure the peak in Figure 1 very accurately.
Words and phrases such as "a little", "easy", and "very accurately" have no definite meaning, and are therefore inadequate. Quantitative, or semi-quantitative, descriptions and analyses are always preferred over the use of such imprecise terms. In the following rewrite, the error is much more clearly described:
The largest source of error is vibration, which is estimated at 1-5 W/kg RMS. This adds at most a 4% uncertainty to the peak integration, and values obtained are therefore reported as +- 4%.
Although you should strive to describe experiments in sufficient detail to be reproduced, it is also important to write concisely. Often, text can shortened by condensing or rephrasing without decreasing the meaningful content. In the two examples below, the latter conveys the same information in a more concise, and preferred, writing style.
Distillation fractions three and four were combined in a 100ml round-bottom flask. To this flask was added 1.966g (0.0114 mol) of benzoic acid. The flask was then connected to a long column, distilling head, and condenser. Glass-wool and foil was again wrapped around the column and distilling head.In a 100 mL round bottom flask equipped with a water jacketed condenser and wrapped column and head, 1.966 g (0.0114 mol) of benzoic acid was added to the combined third and fourth fractions.
4. Revise and proofread
Treat your first written copy as a draft, and then read through and revise. In WIC courses, some assignments will have revision steps included in the submission and grading process. Many students are surprised at how many simple errors can be found in first drafts, and how much their writing improves after using this simple method. A final proofreading is also important, and can help to minimize spelling and typographical errors. A few minor errors are almost inevitable in any written document, but reviewers, and instructors, can usually tell when they are reading a first draft. Along with a "human" proofread, use a spell check routine to help spot errors.
Presenting data...the good, the bad, and the ugly
Reports should usually include a narrative text that describes and explains the information presented. Use the results section to explain the purpose of every figure, schemes, equation and table. Published research results never include "orphan" data, that is, information that is not explained or put into context by the written text. This is also a good rule to follow in lab reports.
When referring to a figure, table, or equation, use its number in the text, for example:
A plateau was observed at reduced pressures greater than 0.1, as indicated in Table 1.
It follows that every figure, table and equation needs a number. Figures and tables require a caption that includes the number and a descriptive title:
Figure 1. Mass uptake vs. reduced pressure for Zeolite 5A.
Table 1. Powder Diffraction Data Obtained for Zeolite 5A.
Note that the labels "chart" and "graph" are somewhat antiquated terms, and have been largely replaced by "figure". Equations will normally have a number placed in parentheses at the right margin:
Here are some additional tips for preparing figures and tables:
- All graph axes require labels that include both the variable name and units.
- Axes should use reasonable scales to clearly show the data and have labeled tic marks. The axis labels do not need to show the full number of significant figures.
- Table columns should specify the units employed under each heading.
- Table entries do generally need to indicate the appropriate number of significant figures (you may need to adjust the spreadsheet column formats appropriately).
Instructors (and editors) can be picky about writing conventions. Literature citations, symbols, and abbreviations all require strict adherence to a standard format. Unfortunately, the particular standard used varies between publishers. An important standard is that adopted by the American Chemical Society (ACS), and this will be used by many chemistry lab courses at OSU. It would be quite difficult to memorize all the forms for literature citations alone. Fortunately, there is no need to do so. The ACS Style Guide (see above) lists all the required formats and provides easily-followed examples. Nevertheless, it's useful to be familiar with the most common citation formats and abbreviations. Some frequently-used ACS formats are provided below.
In the sciences, results are usually discussed in relation to the work of others. Your writing will therefore often refer to results or conclusions that are not your own. This is fine as long as you clearly distinguish between your results and those obtained from other workers or the literature. Each time outside results are cited, a reference must be provided to the original source.
A related issue lies in the use of quotes from another work. The exact duplication of text from an outside source is acceptable only if it is placed in quotations and a reference provided. Paraphrasing or summarizing other results can also be acceptable if a reference is provided. However, incorporating another authors words or style into your own writing is not allowed, even if the original work is referenced. A discussion of this issue and some useful examples of acceptable vs. unacceptable use are provided in "Avoiding Plagiarism @ Oregon State University" at http://oregonstate.edu/admin/stucon/plag.htm
When there are group assignments or reports, make certain that you understand the instructor's expectations for shared vs. individual contributions. Students often do experimental work in groups, and are encouraged to discuss the lab results and data analyses with others. However, report writing is most often expected to be an individual effort.
Test your writing IQ
Here are some links to online quizzes about writing. Each site has a large number of quizzes with answers provided. Try some and see how you rate.