Ferdie is spending too much time playing softball and not enough time studying, so he signs up for "sportaholic therapy" (ST)

The therapist tells him the cure for his "addiction" is to quit softball cold turkey and tap his temples three times whenever he feels the urge to play. After a few months, Ferdie announces that ST isn't helping and he's going to stop coming. The therapist gives him testimonials of other clients who swear by ST, explaining that Ferdie's doubts are actually a sign that the therapy is working. What is the scientific flaw in this argument? (Bonus: What kind of therapy might help Ferdie manage his time better?)

What will be an ideal response?

The therapist has violated the principle of falsifiability (see Chapter 2). If Ferdie is helped by the treatment, that shows it works; if he is not helped, that still shows it works and Ferdie is simply denying its benefits. Also, Ferdie is not hearing testimonials from people who have dropped out of ST and were not helped by it. (Bonus: A good behavioral time-management program might help, so Ferdie can play softball and get other things done, too.)