The application of multiple instruments for measuring structural characteristics of complex organizations in recommended in order to determine their convergent and discriminant validity. This exploratory study makes a comparison between two different sets of measures, designed to assess the degree of centralization and formalization. One set represents the institutional approach, which relies on documents and informants; the other set relies on the survey approach, which is characterized by the use of questionnaires and interview schedules. The simultaneous application of the two sets of instruments to a small sample of manufacturing organizations uggests a certain amount of convergence, but raises serious doubts about the validity of some of the indicators. The differences in scope of the impirical referent of the indicators appear to be a major source for the lack of convergent validity.