This paper presents and illustrates a technique that can be used to analyze the internal and external influences on community college enrollment trends and staffing patterns in a way that quantitatively expresses the amount of increase or decrease attributable to various competing factors. Introductory material relates the rationale behind the Washington State Board for Community Colleges' choice of a statistical approach for its comprehensive review of the status of the community college system. Next, a formal mathematical presentation of the descriptive statistical approach chosen, which is based on decomposition analysis, is presented, followed by an outline of the technique's limitations, particularly the fact that the order in which variables are introduced affects the outcome of the analysis. Then three examples, using actual data from the Washington community college system, highlight the application of the technique and its value in ascribing weights to different factors in explaining: (1) changes in community college participation rate over time and the contribution to these changes by the population's sex-structure, age-structure by sex, and participation rate structure; (2) differences in participation rates between two community college service areas; and (3) changes in faculty/student ratios at a specific college over time. The paper concludes with a discussion of how the technique can be used to analyze changes in institutional practices. (HB)