The principles of andragogy, as explained by M. S. Knowles, in contrast to pedagogy, provide a frame of reference for a differentiated approach to inservice teacher education. Adults are self-directing and ready to learn when they experience a need to know or do something, are life-, task-, or problem-centered, are motivated by both internal and external forces, and bring with them a variety of life experiences. Adult educators, therefore, become resource persons and facilitators of learning rather than instructors. Teachers entering an inservice program are at different stages of development and have different needs and learning styles. The Individualized Learning Modules (ILM) format, a competency-based model for inservice teacher education, provides ways to respond to both the characteristics of adult learners and the diverse needs of teachers. Each learning module addresses specific topics and is designed to achieve one or more independent objectives. The ILM includes a self-assessment of needs, content delivery, sources for further investigation, individual study guide, collaborative group learning guide, performance products suggestions, log form, and evaluation form. Participants select the modules or units that will meet their individual needs. The design of an inservice program using well-defined learning modules assures flexibility and provides a means for responding to a variety of needs in a context of mutual respect and collaboration. (AMH)