Differentiation of Self Inventory—Short Form: Development and Preliminary Validation

In a series of three studies we constructed the Differentiation of Self Inventory—Short Form (DSI-SF) and established initial evidence of reliability and validity. In study 1, we used Item Response Theory to reduce the number of items on the Differentiation of Self Inventory—Revised (Skowron and Schmitt in J Marital Fam Ther 29(2):209–222, 2003 . doi: 10.1111/j.1752-0606.2003.tb01201.x ). DSI-SF scale items were chosen based on full length scale item content and item characteristic curves. Study 2 provided evidence for criterion, construct, and structural validity of the DSI-SF. Specifically, scores on the DSI-SF were positively related to self-esteem and negatively related to symptoms of depression, state anxiety, trait anxiety, and perceived stress. Evidence of convergent validity was found in a positive relationship between the subscales of the DSI-SF and the Level of Differentiation of Self Scale (Haber in The measurement of nursing outcomes, 2nd edn. Springer, New York, pp 320–331, 2003 ). The DSI-SF subscales and full scale were also shown to retain most of the reliability of the full length scales. In the third study, preliminary estimates of 4-week test–retest reliability ranged from 0.72 (Fusion with Others subscale) to 0.85 (DSI-SF Full Scale). These results support the DSI-SF in college student samples.