How to write and publish a scientific paper - Barbara Gastel, Robert A. Day 2022

Some basics
Use and misuse of english
Scientific style

Long words name little things. All big things have little names, such as life and death, peace and war, or dawn, day, night, love, home. Learn to use little words in a big way—It is hard to do. But they say what you mean. When you don’t know what you mean, use big words: They often fool little people.

—SSC BOOKNEWS, July 1981

Some basics

Keep It Simple

Earlier chapters of this book outlined the various components that could (and perhaps should) go into a scientific paper. Perhaps, with this outline, the paper won’t quite write itself. But if this outline, this table of organization, is followed, the writing might be much easier than otherwise.

Of course, you still must use the English language if you want your work to have the greatest visibility. For some, this may be difficult. If your native language is not English, you may face particular challenges in English-language writing; some suggestions for overcoming those challenges appear in chapter 34. Even if your native language is English, you may have a problem because the native language of many of your readers is not English.

Learn to appreciate, as most manuscript editors have done, the sheer beauty of the simple declarative sentence (subject, then verb, then object). You will thereby avoid most serious grammatical problems and make it easier for people whose native language is not English. You also will make it easier for readers who are busy—as almost all readers of scientific papers are.

Tense in Scientific Writing

One special convention of writing scientific papers is very tricky. It has to do with tense, and it is important because proper usage derives from scientific ethics.

When a scientific paper has been validly published in a primary journal, it thereby becomes knowledge. Whenever you state previously published findings, ethics requires you to treat the work with respect. You do this by using the present tense. It is correct to say, “Streptomycin inhibits the growth of Mycobacterium tuberculosis (13).” Whenever you state previously published findings, you should use the present tense, as you are referring to established knowledge. You would do this just as you would say, “The Earth is round.” (If previously published results have been proven false in later experiments, the use of past rather than present tense would be appropriate.)

Your own present work must be referred to in the past tense. Your work is not presumed to be established knowledge until after it has been published. If you determined in your study that the optimal growth temperature for Streptomyces everycolor was 37°C, you should say, “S. everycolor grew best at 37°C.” If you are citing previous published work (even possibly your own), it is then correct to say, “S. everycolor grows best at 37°C.”

In the typical paper, you will normally go back and forth between the past and present tenses. Most of the abstract should be in the past tense because you are referring to your own present results. Likewise, the materials and methods and the results sections should be in the past tense, as you describe what you did and what you found. On the other hand, much of the introduction and much of the discussion should be in the present tense because these sections often emphasize previously established knowledge.

Suppose that your research concerned the effect of streptomycin on S. everycolor. The tense would vary somewhat as follows.

In the abstract, you would write, “The effect of streptomycin on S. everycolor grown in various media was tested. Growth of S. everycolor, measured in terms of optical density, was inhibited in all media tested. Inhibition was most pronounced at high pH levels.”

In the introduction, typical sentences might be, “Streptomycin is an antibiotic produced by Streptomyces griseus (13). This antibiotic inhibits the growth of certain other strains of Streptomyces (7, 14, 17). The effect of streptomycin on S. everycolor is reported in this paper.”

In the materials and methods section, you would write, “The effect of streptomycin was tested against S. everycolor grown on Trypticase soy agar (BBL) and several other media (Table 1). Various growth temperatures and pH levels were employed. Growth was measured in terms of optical density (Klett units).”

In the results. you would write, “Growth of S. everycolor was inhibited by streptomycin at all concentrations tested (Table 2) and at all pH levels (Table 3). Maximum inhibition occurred at pH 8.2; inhibition was slight below pH 7.”

In the discussion. you would write, “S. everycolor was most susceptible to streptomycin at pH 8.2, whereas S. nocolor is most susceptible at pH 7.6 (13). Various other Streptomyces species are most susceptible to streptomycin at even lower pH levels (6, 9, 17).”

In short, you should normally use the present tense when you refer to previously published work, and you should use the past tense when referring to your present results.

The main exceptions to this rule are in the areas of attribution and presentation. It is correct to say, “Smith (9) showed that streptomycin inhibits S. nocolor.” It is also correct to say, “Table 4 shows that streptomycin inhibited S. everycolor at all pH levels.” Another exception is that the results of calculations and statistical analysis should be in the present tense, even though statements about the objects to which they refer are in the past tense; for example, “These values are significantly greater than those of the females of the same age, indicating that the males grew more rapidly.” Still another exception is a general statement or known truth. Simply put, you could say, “Water was added and the towels became damp, which proves again that water is wet.” More commonly, you will need to use this kind of tense variation: “Significant amounts of type IV procollagen were isolated. These results indicate that type IV procollagen is a major constituent of the Schwann cell ECM.”

Active Versus Passive Voice

Let us now talk about voice. In any type of writing, the active voice tends to be more powerful, more precise, and less wordy than the passive voice.

Some exceptions do exist, though. As noted in Chapter 11, passive voice (for example, “the tubes were centrifuged” rather than “we centrifuged the tubes”) sometimes works well in the methods section. Elsewhere in a scientific paper, however, it rarely should be employed.

Why, then, do scientists use so much passive voice? Perhaps this bad habit results from the erroneous idea that it is somehow impolite to use first-person pronouns. Because of this idea, the scientist commonly uses verbose (and imprecise) statements such as, “It was found that” in preference to the short, unambiguous “We found.”

Young scientists should renounce the false modesty of their predecessors. Do not be afraid to name the agent of the action in a sentence, even when it is “I” or “we.” Once you get into the habit of saying “I found,” you will also find that you tend to write “S. aureus produced lactate” rather than “Lactate was produced by S. aureus.” (Note that the “active” statement is in three words; the passive requires more.)

You can avoid the passive voice by saying “The authors found” instead of “it was found.” But compared with the simple “we found,” “the authors found” is pretentious and imprecise (which authors?).

Singulars and Plurals

When you use first-person pronouns, use both the singular and the plural forms as needed. Do not use the “editorial we” in place of “I.” The use of “we” by a single author is outrageously pedantic.

A frequent error in scientific papers is the use of plural forms of verbs when the singular forms would be correct. For example, you should say, “10 g was added,” not “10 g were added.” This is because a single quantity was added. Only if the 10 g were added 1 g at a time would it be correct to say, “10 g were added.”

The singular-plural problem also applies to nouns. The problem is severe in scientific writing, especially in biology, because so many of the words are, or are derived from, Latin or Greek. Commonly, these words retain their Latin or Greek plurals; at least they do when used by careful writers.

(“Piled Higher and Deeper” by Jorge Cham. www.phdcomics.com)

Many of these words (for example, data, media) have entered popular speech, where the Latin a plural ending is rarely recognized as plural. Most people habitually use “data is” constructions and probably have never used the real singular, datum. In The Careful Writer, Bernstein (1965) objected to this usage, terming it “a common solecism.” Today, although debate on the subject persists, both the plural and the singular usages are commonly acceptable, at least in informal contexts. For instance, Merriam-Webster’s Collegiate Dictionary (11th edition) gives “the data is plentiful” as an example of accepted usage. Whether to use data as a plural or a singular word can depend on whether you are referring to a group of individual pieces of data or the data as a single mass. Often, in deciding whether to use data with a plural verb or a singular one, the best approach is to follow your discipline’s conventions in this regard and the predominant usage in your target journal.

This “plural” problem was commented upon by Sir Ashley Miles, the eminent microbiologist and scholar, in a letter to the editor of ASM News (44:600, 1978):

“A Memoranda on Bacterial Motility.” The motility of a bacteria is a phenomena receiving much attention, especially in relation to the structure of a flagella and the effect on it of an antisera. No single explanatory data is available; no one criteria of proof is recognized; even the best media to use is unknown; and no survey of the various levels of scientific approach indicates any one strata, or the several stratae, from which answers may emerge. Flagellae are just as puzzling as the bacteriae carry them.

Numbers

The preferred usage regarding numbers varies among style manuals and among journals. The Chicago Manual of Style (2017) favors “spelling out whole numbers from zero through one hundred” and using numerals for other numbers. However, it notes that many publications, for example in science, spell out only single-digit numbers. In the “revised or modern scientific number style” (Style Manual Subcommittee, Council of Science Editors 2014), single-digit whole numbers, with few exceptions, appear as numerals too.

If the style for numbers is not specified otherwise, here are some widely acceptable guidelines to follow: One-digit numbers should be spelled out; numbers of two or more digits should be expressed as numerals. You would write “three experiments” or “13 experiments.” Now the exception: With standard units of measure, always use numerals. You would write “3 ml” or “13 ml.” The only exception to the exception is that you should not start a sentence with a numeral. You should either reword the sentence or spell out both the number and the unit of measurement. For example, your sentence could start “Reagent A (3 ml) was added” or it could start “Three milliliters of reagent A was added” or “In total, 3 ml of reagent A was added.” Actually, there is still another exception. In a sentence containing a series of numbers, at least one of which is of more than one digit, all of the numbers generally should be expressed as numerals. (Example: “I gave water to 3 scientists, milk to 6 scientists, and beer to 11 scientists.”)

English as an evolving language

“But my fourth-grade English teacher said never to.…” “But I know I read somewhere that this was right.…” “But for my first paper, the journal changed it to be the opposite way.…”

Although the basics of good English remain the same, English keeps evolving as a language— and thus, so do the norms that style manuals recommend and journals follow. Some relatively recent examples: The word “internet” no longer normally is capitalized. The term “underway” no longer tends to be two separate words. And it is now considered acceptable to use the word “they” as a singular pronoun for an individual whose gender is not specified.

So, what’s an author to do? Don’t worry if you can’t keep up with such matters. A journal won’t reject your paper because you still wrote “e-mail” rather than “email.” Luckily, journals have experts—manuscript editors—whose remit includes keeping up with such changes. In editing your paper, these experts help ensure that the English complies with current norms. Appreciate their services. Don’t argue with them that “My fourth-grade English teacher said.…”