The use and interpretation of unstandardized and standardized effect sizes in psychology: current practices and challenges
摘要
Effect sizes quantify the outcome of empirical studies and thus provide the crucial answer to the research question. Unstandardized effect sizes do so in absolute terms, i.e., in terms of the values of the scales used, and are therefore generally easy to interpret. Standardized effect sizes, on the other hand, are a relative piece of information with the advantage that they are free from arbitrary units. However, since many commonly used effect sizes take the variance into account, they carry the risk of being misinterpreted or overinterpreted. In Study 1, the typical use of effect sizes in psychological research was analyzed. Results indicate that although effect sizes are almost always reported, they are most often reported primarily in standardized form, and conventions are most often used to interpret them, most commonly those of Cohen (