Abstract

This chapter presents methods for comparing structural equation models among groups. It begins by giving a general definition of multigroup analysis and by describing the objectives and utility of this type of analysis. The chapter then introduces an hypothetical example for multigroup analysis that involves the effects of fire on the relationship between soil properties and plant production in ecological communities. An overall description of the steps in a multigroup analysis is presented, which includes the initial assessment of baseline models for the separate groups, followed by tests for invariance in parameters among groups. These procedures are then illustrated using the data from the hypothetical example. Finally, a discussion of the possible uses of multigroup analyses for ecological problems is presented. It is concluded that multigroup analyses using structural equations has a wide range of applications for ecological and evolutionary studies, including both experimental and descriptive data.