Trends in assertion training research and practice: a content analysis of the published literature

Investigated historical trends in the assertion training literature by content analyzing 344 documents published between January 1942 and December 1977. Documents were collected through standard literature and search procedures and were content-coded according to their primary methods (e.g., case study, experimental research) and major foci (e.g., assessment, treatment). The results of four separate descriptive analyses performed on the coded reports revealed that although the assertion training literature has shown a very rapid acceleration of growth over the past five years, empirical documentation of the effects of a few important parameters of training and treatment is lacking. Future research needs that clearly emerged from the analyses were discussed.