The Callan Method is based on actual classroom practice, on the psychological teacher-student relationship, and on their relationship to the language. When the Method was shown to some educational psychologists, one of them said "How else?". In other words, as language learning is a question of developing quick reflexes, how else can this be done than by a system of stimulus and response? The same psychologist went on to take an exaggerated example, by adding that one could teach a monkey to play the piano, given such techniques.