Do you think the psychologist's conclusions are correct? Why or why not?

Question

What will be an ideal response?

Answer 1

A woman sought treatment for her symptoms of depression and anxiety. The psychologist, after checking his references for the best treatment given her symptoms, began twice-a-week cognitive-behavioral psychotherapy. By the end of eight weeks, she reported that she was much better, and had only occasional symptoms of depression and anxiety, which she considered to be normal. The psychologist wrote a report describing the results of his study, stating that her improvement offers conclusive support for the effectiveness of cognitive-behavioral therapy.
There are two important reasons to suspect the psychologist's conclusions. (1) It is difficult to draw firm cause-effect conclusions (i.e., causal inferences) based on evidence from case studies. It's likely that extraneous variables were not controlled and that several "treatments" were applied simultaneously. For example, the woman may have started an exercise program at the same time as treatment or may have consulted with others (e.g., friends, clergy) regarding her depression and anxiety. These variables serve as confoundings that limit the internal validity of the case study. (2) Another important factor that limits the ability to make causal inferences based on the case study is that observer bias and biases in data collection may be present. Because the psychologist served both as the therapist and the researcher, his observations may be biased by his dual roles. In addition, the observations of the client's improvement are based on her self-report, and she may be biased to report improvement (e.g., to please the psychologist or to justify the twice-per-week sessions).