7. Clarity and precision

In English, it is a stylistic virtue to be concise and to use the precise phrasing for an idea, and in science, precision and clarity are necessary. In this sense, the demands of style and science coincide. In scientific writing, many wordy constructions can be tolerated until too many of them combine to cloud the meaning. Likewise, poetic language and puns that work well in other contexts should be avoided in scientific articles as much as possible, especially when some readers may not be able to appreciate them. On the other hand, some metaphors have legitimately entered into the terms of some specialties, and other expressions are so common that they have become clear to close colleagues, but not necessarily to the whole community. The LEs keep these factors in mind as they edit.

7.1 Conciseness

Take a look at the discussions and lists on several websites (e.g., Capital Community College’s Guide to Grammar and Writing 2 and in all style manuals in English (e.g., Strunk & White [http://www.bartleby.com/141/strunk5.html#13]) for confirmation of the principle and for abundant examples in the common language, but the following are typical of the language we see in A&A papers.

2 http://grammar.ccc.commnet.edu/grammar/concise.htm

7.1.2 Avoid redundancy

When one word repeats the same idea as the other, then it is not needed, even for emphasis. See Sect. 8 (Frequent changes) for other examples.

decreases down decreases  close proximity proximity
on the order of a few a few  circle around (orbit) circle (orbit)
the point of onset of the onset of  is of fundamental importance is important;
is fundamental
the obtained results the results  coupled together coupled
such as, e.g., such as OR for example  effect due to effect of
the existence of OR the presence of when the noun after it implies that meaning (see below).

7.1.3 Avoid wordy constructions.

As in:

The data reduction was performedThe data were reduced
has a tendency to tends to
at the present time now, nowadays, currently
in spite of the fact that although; even though
due to the fact that because
in the case of X for X; about X
detect the presence of an atmosphere to detect an atmosphere
perform an identification to identify
Concerning the explosion, its effect is… The effect of the explosion is…
The intersection of X and Y occurs X intersects Y
We aim at estimating We estimate
make a comparison with to compare
shows strong indications of X indicate X strongly
is in contradiction with contradicts
is in agreement with agrees with
Before proceeding further, it is worth commenting at this point that we have studied the…We have studied the…

7.1.4 Aim for direct and active phrasing.

Avoid the double negative in favor of a direct, affirmative statement, because not indicating the precise degree is ambiguous and the double negative only tells what it is not: e.g., “This result is not unlikely” can be either “This result is possible” or “This result is likely”.

Use indirect introductory phrasing only when direct phrasing may not be possible, as in “It has been suggested that…”. See Sect. 6.2.1. for examples of when this becomes a problem.

Whenever possible, use the active verb form rather than the equivalent noun phrase, which is wordy and which is already required so often in science writing that using more than is required means that the style quickly becomes too convoluted.

“the estimation of x is”

“estimating x is”

“We observe the planet by the detection of the stellar light it reflects”

“We observe the planet by detecting the stellar light it reflects”

or, better, “We detect the planet by the stellar light it reflects.”

7.2 Ambiguity

Ambiguity often occurs when there is an error or awkwardness in the phrasing so thatthe LE cannot be certain of what was intended by the author. At this point, the LE suggests a rephrasing, which should then be checked by the author. If the suggestion does not express the intended meaning, then the original needs to be rephrased and checked with the LE (highlight text) or a note sent to the LE with the file explaining more about what was intended, so a new phrasing can be found.

7.2.1 Avoid unclear or imprecise phrases.

Ambiguity often comes from words that have more than one meaning or use, particularly for connecting words that are also used as adverbs, prepositions, and adjectives. One example is “and”, which is overused in English for a more precise connector, whether “then”, “because”, “whereas”, or others. “And” is fine, of course, when addition is the intended connection. See Sect. 8 for more examples of possibly ambiguous words.

Like Do you mean “such as” or “similar to”?
As “while” or “at the same time as” or do you mean “because”? Or is it part of the comparison “the same as”, along with many other uses?
As for “in the same way as for X” or “regarding” or “concerning”?
Since “because” or “after which”?
While “whereas” or “during”?
So “therefore”, “meanwhile”, or “because”?
Quite “very” or “somewhat”?
Rather “instead”, “very”, or “somewhat”?
Further “farther”, “more”, “another”, “again”, “furthermore”, or “an extended”?
Such “this sort of”, “very much”, “these”, etc.?
Issue “problem”, “concern”, “question”, “complication”, “frustration”, or “journal publication”? (This is overused in common speech for many other things than its main use: an important and complex problem or difficulty for debate.)
Fraction a ratio (fraction), “percentage”, “portion”, “amount”, “number”, or other? (In standard English “fraction” implies small or low, so either give the exact value or one of the alternatives if the fraction is greater than about 10-30%. The exact measurement is always better, of course, but definitely avoid “composed of a large fraction (99%) of non-star-forming gas”.)

Imprecise phrasing also occurs when using words that are very close in meaning or in sound:

  • relative to/ compared to/ with respect to
  • affect/ effect/ impact
  • in contrast to/ contrary to/ opposed to/ compared to
  • due to/ owing to/ thanks to (The first tends to be used as an adjective, the others as adverbs.)
  • than/ then
  • insure/ assure/ ensure
  • comprise/ consist of/ be composed of/ include

“Comprise” refers to a whole, which includes the parts that are the object of the verb. What follows the active form of “comprise” must be a complete list of the parts that make up the whole, otherwise use “include”, which signals that the list is of examples, not necessarily of the whole set (so using it with ``e.g." is redundant).

7.2.2 Use the exact measurement.

If not using an actual figure, then at least use the precise adjective for a measurement. English uses adjectives like high/low and greater/less more than other languages, where the equivalents of large/small predominate. Use the following chart of descriptive words in scientific papers to find the standard adjective for the noun for a measurement.

high or low abundance, absorption, accuracy, adiabaticity, background, brightness, contrast, degree, density, energy, extinction, fraction, frequency, latitude, level, luminosity, mass, metallicity, number, obliquity, percentage, precision, pressure, probability, proportion, quality, rate, redshift, resolution, shear, speed (fast, slow), temperature, value, velocity (All are typically indicated by up/down graphs.)
big/large or small amplitude, broadening, diffusivity, momentum, opacity, proper motions, radius, uncertainties
high/low or large/small dispersion, frequency, magnitude, number (also, value in some mathematical contexts, but not all, which LEs cannot judge), number statistics (=reference to the sample size)
wide/broad or narrow range, spread, variety
steep or shallow gradient, slope
long or short burst, length, period, time, timescale
strong or weak acceleration, anisotropy, argument, asymmetry, constraint, contrast, current, dependence, effect, evidence, magnetic field, flow, gradient, instability, pulse, relevance, shear, turbulence, velocity field
tight or loose relationship, constraint, correlation (often same as strong/weak)

Avoid vague qualitative descriptions, such as “rather small” or “very important”, but especially avoid them when you could give the exact measurement rather than just imply a degree of size or importance. Other examples include:

  • “partly true” or “somewhat consistent” (Both are ambiguous, since the adjectives imply an absolute quality.)
  • “the fact that” (Often a fact is not what follows, and usually it is just wordy. See Sects. 5.4.3 and 7.1.2.)
  • “in any case” and other fillers that mean little. (Can it be replaced by “in all cases” or “in either case”?

7.2.3 Check for reference confusion.

Make certain you can define what a pronoun (e.g., it, this, they, one) or reference word (e.g., “the latter” can only refer to a choice between two possibilities) refers to, and then consider whether the reader will see the connection immediately with no other possibilities.

Look again at the subject of a subordinate phrase to make certain it is the same as the noun in the sentence it is related to (see the end of Sect. 6.2.1. on dangling participle phrases).

“Considering only up to the quadrupole interaction and neglecting the o-diagonal interactions, the energy shift for the total angular momentum F = I + J due to the hyperfine interaction is given by Schwartz (1955):…” (The energy shift neither considers the interaction nor neglects the interactions, the author (here, Schwartz) does so, but they are not the subject of this sentence.)

“By considering...., we...” or “When we considered the..., the energy shift...” or “Schwartz (1955) gives the energy shift…, considering…”

(There are other possibilities, e.g., two sentences.)

In the same vein, you need to make certain that the subject of a subordinating logical connector is clear -- “as well as”, “in addition to”, and gerunds that can refer to any of the preceding nouns or verbs -- and make certain that any list that follows them is parallel in construction (Sect. 6.3).

“Emission from gas clouds at lower densities progressively increases in addition to the emission from the dense clouds.”

“Emission from....increases, as does the emission from...”

“Emission both from gas clouds at...and from the dense clouds progressively increases.”

“In this paper we present fluxes in the CI lines of neutral carbon at the centers of some 76 galaxies with far-infrared luminosities ranging from X to Y, as obtained with the Herschel Space Observatory and ground-based facilities, along with the line fluxes of the J=7-6, J=4-3, J=2-1 CO, and J=2-1 13CO transitions.”

(What follows "along with" refers grammatically to what follows “as obtained”, but it makes more sense to be equal to “far-infrared luminosities”. The problem is that “with” introduces both phrases, and therefore one of them needs to be changed: “...X to Y obtained from the...”? See Sects. 6.1.2 and 6.3.)