The Long and the Short of It
The goal of writing, especially scholarly writing, is to convey information. Accomplishing that task certainly involves choosing the right words, but have you also considered the length of the sentences and paragraphs in which those words appear? Onwuegbuzie, Combs, Slate, and Frels (2010) include too-short and too-long paragraphs on their list of common APA Style mistakes. Labeling these style choices mistakes may seem harsh, but if you lose readers because of the style of your presentation, the term is apt.
The troubles that come with lengthy sentences and paragraphs are more obvious than those that accompany short ones. I suspect anyone who reads has, at some point, drifted off in the middle of a long, run-on sentence. And woe be to the person who has his or her reading interrupted in the middle of a page-long paragraph! Good luck finding your place and the train of thought after that. (Whatever you do, please don’t try to write the longest sentence in English; the current record holders are legendary.)
Short sentences (insert obligatory Hemingway reference here) and paragraphs can be easily read and digested, but a bunch of either can be choppy, abrupt, even boring. Imagine a Results section that followed this pattern throughout:
The mean was 8.8.
The standard deviation was 9.9.
The results were nonsignificant.
This would get old fast. (Incidentally, you may want to consider a table rather than short or long sentences for numerical results.)
A blend of long and short sentences in a paragraph is ideal. Paragraph length is a little trickier. Single-sentence paragraphs are discouraged. As for long paragraphs, as noted on page 68 of the Publication Manual of the American Psychological Association, sixth edition, “if a paragraph runs longer than one double-spaced manuscript page, you may lose your readers. Look for a logical place to break a long paragraph, or reorganize the material.”
Have further questions about sentence and paragraph length? Please comment below or write to firstname.lastname@example.org.