Extraneous details are details that are not necessary to include in a particular paragraph. They are details that are NOT related to the theme of a paragraph. Read More...
The resources above cover the following skills:
Text Types and Purposes
Write informative or explanatory texts to examine a topic and convey ideas and information clearly. [W.4.2]
Introduce a topic clearly and group related information in paragraphs and sections; include formatting (e.g., headings), illustrations, and multimedia when useful to aiding comprehension. [W.4.2a]