Pre-test – post-test is a quantitative technique used to measure the difference in responses to the same set of questions before and after a program or service. It compares responses before and after to determine the effect of the program. Advantages include measuring self-assessment and recall, while disadvantages include potential validity issues from testing effects, maturation, and bias. The document provides tips on question design and alternatives to standard pre-test post-test to improve validity, such as using diaries, role plays, control groups, or informants.