The meaning and suitability of various effect sizes for structured rater x ratee designs.

Four types of analysis are commonly applied to data from structured Rater × Ratee designs. These types are characterized by the unit of analysis, which is either raters or ratees, and by the design used, which is either between-units or within-unit design. The 4 types of analysis are quite different, and therefore they give rise to effect sizes that differ in their substantive interpretations. In most cases, effect sizes based on between-ratee analysis have the least ambiguous meaning and will best serve the aims of meta-analysts and primary researchers. Effect sizes that arise from within-unit designs confound the strength of an effect with its homogeneity. Nonetheless, the authors identify how a range of effect-size types such as these serve the aims of meta-analysis appropriately.