A remotivation team in a psychiatric hospital conducted an experiment to compare five methods for remotivating patients. Patients were grouped according to level of initial motivation. Patients in each group were randomly assigned to the five methods. At the end of the experimental period the patients were evaluated by a team composed of a psychiatrist, a psychologist, a nurse, and a social worker, none of whom was aware of the method to which patients had been assigned. The team assigned each patient a composite score as a measure of his or her level of motivation. The results were as follows:
Level of Initial Motivation Remotivation Method ABCDE Nil 58 68 60 68 64 Very low 62 70 65 80 69 Low 67 78 68 81 70 Average 70 81 70 89 74 Do these data provide sufficient evidence to indicate a difference in mean scores among methods? Let a ¼ :05.