Abstract
Proposed is a comprehensive, multivariate, multi-realm theoretical framework with which to integrate and advance the theory and research on adult education participation (AEP). The elements of the ISSTAL model, as elaborated by D. H. Smith, are identified, defined, and exemplified in terms of the current literature on AEP. This article describes elements of the framework which have already been investigated and those for which there are gaps in the literature. Suggestions for further research to close those gaps are given. The framework has significance for theory and research on AEP as Well as more general theory-building efforts in adult education.