This paper is about the structural equation modelling of quantitative measures that are obtained from a multiple facet design. A facet is simply a set consisting of a finite number of elements. It is assumed that measures are obtained by combining each element of each facet. Methods and traits are two such facets, and a multitrait-multimethod study is a two-facet design. We extend models that were proposed for multitrait-multimethod data by Wothke (1984;1996) and Browne (1984, 1989, 1993), and demonstrate how they can be fitted using standard software for structural equation modelling. Each model is derived from the model for individual measurements in order to clarify the first principles underlying each model.