[Possible definitions and subsequent incidence of circumscribed reading and spelling disorders--theoretical considerations and empirical findings in a representative sample of young adults].

OBJECTIVES

With reference to an epidemiological sample of adolescents and young adults the impact of different models on the number of children classified as having specific reading and spelling problems is investigated.

METHODS

Using the same set of data, the effects of alternative measurement models, definitions and methodological procedures on the prevalence of specific spelling problems are shown. The virtual consequences of various norm-oriented definitions of cases are discussed with reference to external empirical criteria.

RESULTS

In the present study case definitions of specific spelling retardation based on substantial criteria result in prevalence rates between six and nine percent.