DATA AGGREGATION - CRITERIA FOR PSYCHOMETRIC EVALUATION

Criteria for the examination of data collected at the individual level and aggregated to the group are proposed. These four empirical criter ia relate to content validity, representativeness, reliability, and va lidity of the aggregated scores as indicators of group phenomena. An e xample of the use of the criteria is provided using data from a large research project on the implementation of a professional practice mode l on nine nursing units. The use of the criteria proposed provide a sy stematic approach to the evaluation of individual data for use at the group level. (C) 1995 John Wiley & Sons, Inc.