The Effects of Item Placement in the Young Schema Questionnaire.

The Young Schema Questionnaire (YSQ) was developed to measure Early Maladaptive Schemas (EMS), a construct central to Schema Therapy (ST). Traditionally YSQ items were placed in a grouped format for each schema but in recent versions of the questionnaire, items are presented in a random order. This study investigates the effect of item placement on the psychometric properties of the questionnaire. On different occasions, participants completed two versions of the YSQ short form, one with items grouped according to schemas and another where items were placed in a random order. Responses were analysed using the polytomous Rasch model of measurement (partial credit parameterization). Results show that the two versions are not psychometrically equivalent. There were greater differences between the clinical and non-clinical group means for the grouped format than the random format and greater person separation. There was more response dependence between items in the grouped format which has been linked to inflated reliability indices.