The present analysis examines the data and method for investigating the social structure of communicative competence. Specifically, the article details a case-study methodology for exploring social-support network effects on communicative competence. The rationale for a social-network perspective and a brief literature review of communicative competence and social-network research are presented in the first section. Next, issues pertaining to the selection of social-network cases and data-collection instruments are discussed. Following that, an analysis of a multiple-case study performed using the described methodology is discussed and critiqued. A multiple-case study of expatriates living in Southeast Asian cultures is then presented. For each case, the network of relationships is described structurally, focusing on network composition, dependency relationships, density, reciprocity, the adjustment process, and sociolinguistic identity. Specific social-network characteristics are found to influence the expatriates' communicative competence.