Imagine you are reading a report on your business unit’s performance during the third quarter. Nearly every paragraph takes up about half of a single-spaced, typed page — page after page after page. What is the effect on you, the reader?
Probably exhaustion, because the writer has most likely included too many ideas in each paragraph, thus leaving it up to you to understand which sentences go together and what the relationship among the various ideas is.
Generally, a body paragraph should contain one main idea, often called the topic sentence, on which the writer elaborates. There are exceptions, but many paragraphs follow this format — and many of those that don’t, should.
When you signal the start of a new paragraph (by indenting, or skipping a line, or both), you are signaling to the reader the start of a new thought. Paragraphing is an example of how form — in other words, the appearance of a document — supports content.
Now, imagine you are reading a report that strings together a series of extremely short paragraphs. Is this an improvement over the collection of excessively long paragraphs? Not necessarily. Writers who overuse short paragraphs often create a choppy, disjointed effect.
As in most things, moderation — manifested through a mixture of short, medium-length, and longer paragraphs — is often the best approach.