The German Self-Report Version of the Strengths and Difficulties Questionnaire (SDQ-Deu-S): Psychometric Properties, Factor Structure, and Critical Values

The present study examines factor structure, psychometric properties, and critical values of the German self-report version of the Strengths and Difficulties Questionnaire (SDQ-Deu-S). The data of this study are based on a sample of 1501 children and adolescents aged 11 to 16 years. The assumed five-factor structure was confirmed by exploratory as well as confirmatory factor analyses. However, the reliability of the five scales (Cronbach's alpha .55-.77, retest .58-.67) was low. Only the Total Difficulties Scale revealed a satisfactory internal consistency. Gender-and age-specific critical values are suggested based on Goodman's (1997) target of having 80%, 10%, and 10% in the normal, borderline, and abnormal categories, respectively: The critical values for most of the SDQ subscales are one point lower and for the Total Difficulties Scale no more than two points lower than the recommended critical values for the British SDQ self-report version of Goodman, Meltzer, and Bailey (1998).