A few years back I was stalked. You’d think they could have found someone a bit more interesting to stalk, but apparently times were hard. It wasn’t particularly pleasant, but could have been a lot worse. I imagined a world in which a psychologist tried two different therapies on different groups of stalkers (25 stalkers in each group – this variable is called therapy). To the first group he gave cruel-to-be-kind therapy (every time the stalkers followed him around, or sent him a letter, the psychologist attacked them with a cattle prod). The second therapy was psychodyshamic therapy, in which stalkers were hypnotized and regressed into their childhood to discuss their penis (or lack of penis), their dog’s penis, the seventh penis of a seventh penis, and any other penis that sprang to mind. The psychologist measured the number of hours stalking in one week both before (stalk_pre) and after (stalk_post) treatment (stalker. sav). Analyse the effect of therapy on stalking behaviour after therapy, adjusting for the amount of stalking behaviour before therapy.