The research tradition within Peplau's theory has been to use case studies based on process recordings A disadvantage of this approach is that it has usually been limited to the study of a single nurse-client dyad at a tune, and generally no comparisons between dyads have been made Also, this approach was generally used to demonstrate the use of the theory, based on an assumption that the theory reflected reality, rather than testing this assumption In American and Canadian surveys, Peplau's theory has been identified by at least half the psychiatric nursing samples as the theory which guides their practice (Marbn & Kirkpatnck 1987, 1989, Hirschmaim 1989) Despite vnde use m practice, Peplau's theory has not been empirically tested through research