Progressive reinforcement schedules (i.e. progressive ratio or interval schedules) have had limited use. What studies have been done show them to be valuable in testing perseverative hypotheses. Using these schedules the effects of variables that may affect perseveration, or persistence, of behaviour, can be assessed. Such variables are reinforcement magnitude, motivation conditions, and physiological manipulation using drugs, brain lesions and so on.Perseveration has been measured by the total number of responses or the size of the last completed ratio before responding becomes infrequent at the “break‐point”. Other dependent variables, such as the session time or the rate of responding may be used also to measure perseveration. The question of the criterion of the “break‐point” is discussed.The relationship between the different progressive schedules, the property of their aversiveness, the effects of various variables on them and the potential use of these schedules ar