What is a manipulative aid? Describe a situation in which the speaker would want to use a manipulative aid?

When they are in a bad situation

A manipulative aid is any presentation aid that the speaker actively changes during the course of the speech. Writing notes on a chalkboard during a classroom lecture is an example of when a speaker may want to use a manipulative aid. Other examples include: writing ideas from audience participation, or changing an aid during a demonstration speech.