The development of learning environments especially for adults has been neglected and research in planning such environments is fragmented and minimal. There is general agreement that facilities for adults should have an aura of adulthood to contribute to an adult's feeling of ease, confidence, and capability; that they should be flexible in room configuration, ability to change the environment, and availability of multi-purpose equipment; and that social and phychological implications of seating arrangements should be considered. Specific findings cover space, fixtures, and furniture; the use of colors and lighting; other visual and auditory factors such as the disruptive quality of clutter and decrements in hearing ability among adults; and recommended temperature, humidity, and air motion. Sources of further information include the Educational Facilities Laboratories, the Kellogg Foundation, business firms which train large numbers of employees, and hotel and motel chains. A 54-item annotated bibliography of books, articles, and reports and a 6-item listing of bibliographies on educational environments supplement the text. (MS)