Paraphrasing a student's ideas can serve multiple purposes. When used well, paraphrasing indicates to students that they have been heard; used poorly, however, it can distort the student's meaning and refocus attention on figuring out what the teacher is thinking. More about "paraphrasing" here:
Jon Basden paraphrases a student's definition and uses the full mathematical terms, while providing others with an opportunity to elaborate on this definition. Jon is wondering if he moved too quickly from "radius times radius times pi" to "radius squared times pi."
In general, what kinds of regular classroom events impede being able to provide the "ideal" amount of paraphrasing of students' thoughts?