"In these open constructed response items, teachers should foster students' self-evaluation skills. As students read, take notes write and perhaps revise, they are continually self-monitoring." (Guthrie, J. T., 2002, Preparations in Test Formats, para. 10)
Responding has a broad scope. In general terms, it is thinking that is shared in a tailored manner to satisfy a specific prompt. The prompt often determines if the response is more generative or mostly derivative.
Prompts may include short answer, constructed response, extended response, and other prompt types where the structure of the response is stated or assumed by the prompt itself.