Union is Strength: A Consumer's View of Meta-Analysis

Meta-analyses are a textbook author's delight. They can alert authors to the existence of a literature, quantitatively synthesize results, and mitigate overemphasis on vivid but misleading studies. For these benefits text authors pay a price: The need to simplify impedes scrutiny of individual studies and draws attention away from moderating variables and toward the statistical bottom line-the mean effect size.