[Methodologic decisions in evaluation of psychotherapy]

Psychotherapy research makes demands on evaluation studies in regard to content and methodology. These demands, however, are difficult to realize. The expense of a study results in a multidimensional matrix consisting of: the different sources of data, number and extent of the measures on theoretically derived assessment levels, the number of times measures are repeated, and the sample size. Decisions for research methods should be deduced explicitly from the goal of the evaluation study as well as from the goals of the evaluated therapy. Alternatives for the choice of operationalization, test designs, data evaluation and presentation will be reviewed and discussed.