Researchers on close relationships presupposed marriage as a central measure of successful commitment and identified a mix of structural and personal motives underlying commitment. Debate on how to measure and predict commitment has been prompted by its conceptual complexity and the importance of its role in relationship maintenance. This study focused on five couples together for at least 13 years outside the institutional grooves and prescribed roles of marriage. Johnson's (1991a) social-psychological model of commitment types embedded within a social structure guided the research. The couples defined commitment, discussed a challenging time in the maintenance of their relationship, and responded to specific questions. Data analysis resulted in development of a three dimensional model of commitment phenomenology. Dimensions include types of commitment from Johnson's model (1991a); commitment contexts of time and society expanded from Johnson's model; and the expression of commitment (awareness, salience, plans, or behavior) implied in Johnson's model but made explicit in this model. / Master of Science