MEASURING THE COMPOSITION OF VOLUNTARY GROUPS - A MULTITRAIT-MULTIMETHOD ANALYSIS

Data on a sample of 128 face-to-face voluntary groups are analyzed wit h the multitrait-multimethod approach. The traits measured include fou r characteristics: size sex composition, age composition, and educatio nal composition. These four traits are measured with three different m ethods: reports from a respondent chosen through a probability sample from the community, reports from an official of the group, and estimat es from direct measurement of the traits at an organizational meeting. Results of the analysis suggest that the three measures are parallel with one another in the sense of Lord and Novick 1968. This result mea ns that the three methods are equally desirable. Surprisingly, the dir ect canvass measure does nor appear to be more reliable than the other s; on the contrary, it appears to be equivalent to other reports for t he traits measured. There is a slight suggestion in the data that offi cials in the group are more accurate than ordinary respondents in repo rting information about less salient characteristics of the members, s uch as years of education. In general, the three methods of gathering data appear to be equally reliable, although they measure slightly dif ferent aspects of group composition.