How Long Should a Paragraph Be?

How Long Should a Paragraph Be?
Various educators teach rules governing the length of paragraphs. They may say that a paragraph should be 100 to 200 words long, or be no more than five or six sentences. But a good paragraph should not be measured in characters, words, or sentences. The true measure of your paragraphs should be ideas.
Your childhood teacher did not wrong you when he or she taught you that there should be three, or four, or five sentences in a paragraph. It is important to understand, however, that the aim in teaching this was not to impart a hard-and-fast rule of grammar, drawn from an authoritative-but-dusty book. The true aim of this strategy was to teach you that your ideas must be well supported to be persuasive and effective.
The model regarding paragraph length that your teacher undoubtedly taught you involves a topic sentence, a number of facts that support that core idea, and a concluding sentence. The proviso about the number of sentences between the topic sentence and the conclusion was not given to you because it was the magic formula for creating paragraphs of the perfect length; rather, your educator was attempting to give you a good reason to do adequate research on your topic. Academic writing yields the best examples of the topic-support-conclusion paragraph structure.
Recent research has provided a wealth of insight about how dogs came to be domesticated by humans and the roles they played in Native American culture. DNA studies on archaeological finds suggest that dogs may have been domesticated by humans as long as 40,000 years ago. When the first humans came to North America from Eurasia, at least 12,000 years ago, domesticated dogs came with them. They appear to have been highly prized by early North American hunter-gatherers and were their only animal companions for centuries, since there were no horses on the continent until the 16th century.
You can see from this example how a topic is introduced, supported, and then brought to its natural conclusion. Yet, not all writing is academic, and once you have learned the concept behind good paragraph construction—which is really the art of focused writing in disguise—you should know that there are times when paragraph “rules” can, and should, be broken.