The Museum of Science in Boston proposes a major modification of its permanent New England Wildlife Zones exhibition hall in order to improve its effectiveness with visitors with impaired sight, hearing, or mobility. They will document and share with other museums the successful methods and techniques used in the exhibition development process is an effort to improve barrier free access in the country's more than 600 science and natural history museums. The museum has completed a preliminary needs assessment with the assistance of handicapped consultants, developed alternative design solutions to problems of limited accessibility and effectiveness for the hall's existing dioramas, and organized a design team that includes senior museum exhibition and education staff and a handicapped scientist and educator as Co-PI. The Massachusetts College of Art's Adaptive Environments Center will provide assistance in design for the handicapped and evaluation will be under the direction of George Hein, head of Lesley College's Program Evaluatlion and Research Group. Following an extensive design and evaluation process, new exhibit units will be constructed as educational adjuncts to the existing hall of dioramas, and the impact of the changes will be assessed, as part of a dissemination plan that will include popular and professional papers and a "how to" work book distributed to science museum exhibit designers with the assistance of the Association of Science Technology Centers and the American Association for the Advancement of Science. This is a challenging project with the opportunity for a significant impact on handicapped individuals who are often excluded from the motivational and informational resources of science and natural history museums by unnecessary design limitations. The Museum of Science's commitment is strong, the project staff are highly qualified, and there is active participation by handicapped individuals in the project.