PATH 05 - Exam skills 07 Evaluating 'interventions' and essays

Question 1

Describe the Smith and Glass Meta analysis?

Answer 1

• Smith & Glass analysed studies of the effectiveness of therapies which compared a control group (other treatment or no treatment) to a range of therapies
• All of the studies were therefore clinical trials (or randomised control trials)
• They calculated the effect size: this is a statistic used to compare means when different studies have used different measurement scales in the original studies.
• According to Cohen, an effect size of 0.2 is small, 0.5 is medium and 0.8 is large.
• SD had the highest effect size at 0.91

Question 2

Who conducted the meta analysis of psychotherapies?

Answer 2

Smith & Glass