Researchers investigated psychological therapies for clinical depression. They assessed the self-esteem of two groups of participants before they started their respective therapies, and then assessed the same participants again after six weeks of therapy.
Group A (Counseling alone group) received humanistic counseling.
Group B (Combined therapy group) received humanistic counseling combined with Cognitive Behavioral Therapy (CBT).
The researchers assessed self-esteem using a standardized self-esteem questionnaire, with scores ranging from 0 to 80. A lower score indicated lower self-esteem, and a higher score indicated higher self-esteem. The lowest score recorded in the sample was 15 and the highest was 72.
Table 1: Mean self-esteem scores for Group A (Counseling alone) and Group B (Combined therapy) after six weeks of therapy
| Group A (Counseling alone) | Group B (Combined therapy) | |
|---|---|---|
| Mean self-esteem score | 42.1 | 58.6 |
Explain why the data in Table 1 does not enable the researchers to draw valid conclusions about the effectiveness of the therapies for the two groups. State what the researchers should do to address this issue.
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