Definition of "Pointer" I am in the process of writing a review-type paper for my intermediate quantum mechanics course. I have chosen to do my paper on the topic of measurement, with a focus on weak measurement. In all of the papers that I am reading, the term "pointer" is thrown around, but I have not seen it clearly defined as all of the papers assume familiarity with the topic. My (vague) understanding of the pointer is that it is coupled with the measured system and, upon measurement, its value will shift by the measured eigenvalue, at least for a projective measurement. However, I am not entirely sure if this is correct and would greatly appreciate elaboration on what the pointer is in the context of measurement.