supporting detail

A supporting detail is the part of the passage that does the work for the main idea: the reason it holds, the result that follows from it, or the example that shows it. Finding one is a two-part move. First state the point the passage is making; then ask which sentence would be missing if that point had to be argued. The sentence that answers that question is the supporting detail, and the question usually names what it supports (which detail supports the claim that…). The trap is the sentence that is true and merely nearby: a detail about the setting, the schedule or the people can sit beside the point without carrying it. A supporting detail also runs the other way — a question can hand you the detail and ask what it shows, which is the same relationship read backwards.