This paper presents a framework and model for design of open-ended learning environments (OELEs). First, an overview is presented that addresses key characteristics of OELEs, including: use of meaningful, complex contexts; provision of tools and resources; learner reflection and self-monitoring; and social, material, or technological scaffolding. Next, the following assumptions associated with the design of OELEs are discussed: understanding is best achieved when situated in relevant contexts; learners must take more responsibility for monitoring and reflecting upon the learning process; understanding is best supported when learners connect personal experiences with formal concepts; and learning is a byproduct of progressive negotiation and interpretation of meanings. Following establishment of a framework for understanding the challenges and opportunities afforded by OELEs, a theoretical model for designing OELEs is introduced. The following phases and related considerations are described: (1) analysis, including environmental and participant characteristics; (2) design, including objectives, instructional domains, instructional content, means of instruction, and evaluation methods; (3) development and implementation, including resources, and on-going effort; (4) evaluation; and (5) maintenance. Finally, guidelines are offered to assist in use of the model for design and development of learning environments based on open-ended constructs. (Contains 48 references.) (AEF)