ABSTRACT
Before starting with the process of acquiring, correcting and measuring images, it seems important to spend a chapter addressing the important question of just what it is that can and should be measured, and what cannot or should not be. The temptation to just measure everything that software can report, and hope that a good statistics program can extract some meaningful parameters, is both naïve and dangerous. No statistics program can correct, for instance, for the unknown but potentially large bias that results from an inappropriate sampling procedure.
