Executive SummaryThe Advanced Distributed Learning (ADL) Initiative was established by the Office of the Undersecretary of Defense for Personnel and Readiness (OUSD(P&R)) in 1997. Its purpose was to assist the military Services in making "learning" (education, training, and performance/decision aiding) available on-demand, anytime and anywhere."Learning" in ADL is used as a catch-all designator for education, training, and performance/decision aiding. "Distributed" in ADL signifies learning that can be provided in classrooms with a teacher present, in the field linking together widely dispersed instructors and students, or standing alone with no instructor other than the computer itself. "Advanced" in ADL implies affordable, interactive, adaptive, on-demand instruction delivered using computer technology so that it is available anytime, anywhere.Empirical research, available as early as the 1960s, suggested the feasibility of ADL and its goals. It has shown that:• Individualized, tutorial 'learning' (including individualized performance/decision aiding) can be provided affordably by technology-based learning.• Technology-based learning can be more effective and can produce greater return on investment than conventional instructional approaches across many instructional objectives and subject matters.• Technology-base learning allows education, training, performance aiding, and decision aiding to be delivered on platforms ranging from hand-held devices, to desk-top computers, to capabilities embedded in operational equipment.Statistical findings from this research may be summarized by a "Rule of Thirds." It states that application of technology-based learning can reduce the cost of instruction by about one-third. Additionally it can either reduce instructional time to reach instructional goals by about one-third, or increase the skills and knowledge acquired by about onethird while holding instructional time constant.The long-term vision for ADL is an extrapolation from such developments as portable, increasingly accessible computing, the global information infrastructure, modular object-oriented architectures, and natural language processing. The march toward devices that might be described as personal learning associates seems inevitable. These devices will act as personal accessories. They will respond on demand to requests for education, training, and performance aiding by assembling relevant objects from the global infrastructure and engaging the user in guided conversations to enhance the iv knowledge and skills and/or problem solving capabilities of individuals and/or groups of dispersed individuals whose devices are wirelessly linked together.v