Item selection and validation of a brief, 20-item version of the Differentiation of Self Inventory-Revised

The 46-item Differentiation of Self Inventory-Revised (DSI-R) (Skowron & Schmitt, 2003) is perhaps the most widely used and psychometrically validated instrument measuring the family systems theory (Bowen, 1978) concept of differentiation of self. Given the substantial length of the DSI-R, Drake et al. (2015) offered the Differentiation of Self Inventory-Short Form (DSI-SF). However, based on limitations of the DSI-SF, we empirically validated a brief version of the 4-factor DSI-R using data from two adult samples (Sample 1: n = 541; Sample 2: n = 203). First, we conducted an EFA on the full 46-item DSI-R scale on Sample 1 to help us identify items most strongly representing each factor. Then we conducted CFAs comparing the model fit between our brief DSI, the DSI-SF, and the full DSI-R on both samples. Results indicated that the brief DSI had the strongest model fit in both samples. Finally, a comparison of associations among the brief DSI, the DSI-SF, and full DSI-R and various relevant variables showed similar correlations. The brief DSI provides counselors and researchers in the areas of psychology, organizational behavior, and business a useful measure of differentiation of self when circumstances prohibit the use of the full DSI-R. (C) 2016 Elsevier Ltd. All rights reserved.