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Writing Science: Structure 1


Paragraphs are the building blocks of all writing assignments.

Two important features of paragraphs are that (1) they have a single controlling idea and that (2) the controlling idea is supported with relevant details, examples, and analysis. The controlling idea must be summarized in the first sentence, which is often referred to as the topic sentence, and all ideas throughout the paragraph must connect to it. The final sentence should provide a link between the controlling idea and the purpose of the lab report. The first and/or last sentences should also transition between the previous and next paragraphs, respectively. Effective paragraphs are 100 to 200 words in length – too short, and detail is often missing; too long, and more than one controlling idea is often present.

Paragraph checklist
 Contains a single controlling idea
 Begins with a topic sentence that summarizes the controlling idea
 Uses details, examples, and analysis to support and develop the idea
 Is no longer than one printed page (between 100 and 200 words)

Please see the Online Essay Guide for more information on effective paragraphs and transitions.


Sentences are the basic unit of writing. Although seemingly simple, sentences pose many troublesome problems for writers. It is important to understand a few of the most common errors; each item in this list is linked to grammatical instruction available in the ASC Grammar and Clear Writing Module:

A good way to spot errors in sentences, even if you aren’t familiar the terminology, is to read your writing aloud, slowly and carefully. This will highlight awkward structures that you can then rework to correct. Learn about more proofreading strategies in the Writing Science guide.

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