The Usefulness of Unit Weights in Creating Composite Scores: A Literature Review, Application to Content Validity, and Meta-Analysis
Philip Bobko*,
Philip L Roth,
and
Maury A Buster
Gettysburg College
* To whom correspondence should be addressed. E-mail: pbobko{at}gettysburg.edu.
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Abstract |
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Combining/weighting subscores into an aggregate score involves issues that apply to many fields in the organizational sciences (e.g., weighting predictors in selection, weighting multiple performance appraisal indicators, overall evaluation of organizations). The weights that are used in practice can be different (differential weights) or equal (unit weights). Relevant literature across multiple disciplines and multiple decades is reviewed. The literature indicates that unit weights have substantial predictive validity when compared with regression weights, but there is a lack of data on how other differential weighting strategies (e.g., weights generated by subject matter experts) compare to unit weights. In response, a primary and a meta-analytic study are provided here. The recent literature also contains some potential criticisms of unit weights in regard to personnel selection and content validation--and those statements are evaluated. The data and findings indicate that unit weights can be a highly appropriate approach for weighting under many circumstances.
