The term "functional communication" refers to the skills and knowledge possessed by an individual, from which that individual's competence or effectiveness may be inferred. Part one of this two-part book identifies and describes conceptual and methodological issues involved in evaluating, or empirically describing, the major components of interpersonal interaction related to functional communication. Part two contains brief reviews of 90 instruments, observation and category systems, and general assessment procedures designed to generate information on some aspect of an individual's functional communication. The book includes a brief commentary on apprehension and anxiety because of their importance as explanatory variables connected with low levels of functional communication competence. (MAI)