The chief goal of this investigation was to quantitatively evaluate the LLRM and DM, which partially overlap but also make some distinctly diverging predictions. The DM predicts that at-risk groups should demonstrate greater subjective stimulation and greater response on the ascending limb of the BAC curve—or, more specifically, greater stimulation on the ascending limb of the BAC curve in particular—whereas the LLRM predicts that at-risk groups should demonstrate lower response regardless of BAC limb or sedation versus stimulation. Testing these predictions presented an analytic challenge in that many studies compared groups on both BAC curve limbs and on measures of both stimulation and sedation, resulting in a violation of the assumption of independence of effect sizes. Although there are methods available for multivariate meta-analyses, these approaches require information about correlations among outcome measures not available here and may be susceptible to bias when different studies measure different outcomes (e.g., Raudenbush et al., 1988). Because we are aware of no appropriate method to test the within-study moderation effects hypothesized by the DM, we estimated effect sizes for group differences in sedation
