This volume of New Directions for Adult and Continuing Education presents discussions of well-established theories and new perspectives on learning in adulthood. Knowles' andragogy, self-directed learning, Mezirow's perspective transformation, and several other models are assessed for their contribution to our understanding of adult learning. In addition, recent theoretical orientations, including consciousness and learning, situated cognition, critical theory, and feminist pedagogy, are discussed in terms of how each expands the knowlege base of adult learning. This is the 57th issue of the Jossey-Bass quarterly report series New Directions for Adult and Continuing Education.