Active voice is almost always more effective than the passive voice.
(E.g., “We found that the pathogen responded to…”—or even better, just “The pathogen responded to…”—rather than “It was found that the pathogen responded to…”)
Proper punctuation provides a guide for your reader to follow you through your explanation.
Outside of their use as decimal points or other mathematical indicators, periods mark the end of a sentence and a complete thought.
Commas (again, outside of their mathematical usages) separate elements whether those are elements in a list of three or more items;
dependent clauses in a sentence in relationship to a a principal clause; independent clauses joined by a conjunction such as and, but, and or; asides, interjections, or other words of commentary which are not crucial to the structure of the main thought (“This was generally true; however, in the special instance…” or “Nonetheless, this molecule showed activity…”); non-restrictive phrases or clauses from the noun they modify (e.g., “this agent, which is the first in its class, has been effective…”); introductory prepositional phrases which are at least two phrases long (“In the matter of the catalyst, the study showed that…”); appositives.
Except in cases where an appositive or non-restrictive modifying clause follows the subject of a sentence, a comma never comes between a subject and its verb.
Except in instances where you may be writing out a speech or other oral presentation, commas do not belong in a sentence to indicate a pause or need for a breath.If you find yourself tempted to do this, it may be an indication that your sentence is too long-winded and that it might be better broken down into two or three shorter ones.
Semi-colons appear far less frequently than commas. They most commonly serve to:
separate two independent clauses not joined by a conjunction and separate elements in a list of three or more items when one or more of those items contain commas within them.
A series of shorter sentences may be more effective than one long one.
You want your readers to follow you every step of the way.
While some ideas and inter-relationships can only be expressed accurately in complex sentences with a web of independent and dependent clauses, you can communicate many others simply and directly in shorter sentences or paragraphs.
Varying the length and structure of your sentences helps keep readers’ attention focused.
Not everyone will be as good as you are at keeping the relationships among different parts of an idea in mind as they juggle the various elements of your sentence—especially if you’re communicating novel information.
While you are intimately familiar with your topic and the details of your work, your readers are probably not. (If they were, they wouldn’t need to read your piece.) Breaking an idea down into two or more sentences can sometimes make a complex concept more comprehensible.