The determinants of self-directed learning (SDL) among professionals of high attainment were examined through open-ended, semidirected interviews with a purposeful sample of eight professional men and women who have acquired identifiable, high-level professional knowledge/skills typically taught in postsecondary learning institutions without ever having enrolled in postsecondary programs in their field. The informants were recognized professionals in the following fields: computer analysis, structural engineering, media technology, accounting, training, journalism, computer research systems, and management/new media. An analysis of the informants' comments revealed three main elements of the SDL process: (1) emergent goal structure (a fairly clear set of professional objectives from the outset); (2) unusual learning strategies (including hiring consultants on a one-time-only basis, delegating research tasks to employees, validating new knowledge by discussing business with competitors, and modifying learning objectives to match available resources); and (3) "autodidactic leap" (learners took actions that literally forced them to learn on their own, often under considerable pressure). The interviews also established that successful SDL is determined by a combination of personality traits (including creativity, optimism, high capacity for learning, and curiosity) and environmental factors (including particularly stimulating episodes on the job and a boss's or colleague's suggestion that the informant assume new functions or responsibilities). (Contains 14 references) (MN)