Numerous models have been developed to analyze the relationship between adult education, adult learning, and adult development. Squires' contingency model postulates that the how of teaching is determined by the nature and characteristics of the participants (the who), the content (the what), and the setting (the where) in which teaching takes place. In contrast, the noncontingency model postulates that, irrespective of the aforementioned factors, teaching must adhere to fundamental principles or laws relating to the nature of learning itself. The noncontingency model is the basis for four schools of thought regarding education: the behavioristic, cognitive, information processing, and humanistic approaches. Two metaphysical models of development and learning--the mechanistic and organismic models--have also been used to explain the sources of human motivation to change and learn. These models have in turn given rise to many models and theories of adult development and learning. (This document examines the following models: the biological, growth, maturational model; the stability model; the decrement-stability model; the ordered change model; the dialectical model; the contextualist-aleatory model; the life span development model; and the adaptive model of adult cognition.) (MN)