Beschreibung:
<jats:p> This investigation was concerned with the widely spread practice to extract subscales from extensive psychodiagnostic inventories and to present their items in questionnaires as homogeneous item-blocks. By way of examining the effects of the mode of item-presentation on the reliability and validity, the frequently used and validated SCL-90-R was analyzed as a prototype of multidimensional symptom self-report inventories. Two studies were conducted in different contexts of application (study I: controlled group testing, study II: non-controlled individual testing) and involved different groups of subjects (study I: 130 nursing school students, study II: 134 university students). In both studies the standard item-arrangement was contrasted with the item-block presentation, which groups together items measuring the same dimension. The results revealed significant effects of item-blocking on the mean values, on the reliability, and the validity of the questionnaire. The findings seriously call into question the admissibility of subscale-extraction for self-report inventories. We conclude that the Gestalt paradigm, “The whole is more than the sum of its parts,” is valid for multidimensional psychodiagnostic inventories. </jats:p>