This guide was designed for developers of mastery learning materials for competency based learning situations. Topics include: (1) how mastery learning works and how the mastery learning process can be used in the classroom; (2) the advantages of mastery learning; (3) how to determine if mastery learning is right for student needs; (4) how to create the necessary support for the development project within an organization; (5) how to plan for a development project; (6) how to analyze the learning objectives of a unit, course, or program; (7) how to design and develop test blueprints, domain specifications, and items for criterion referenced tests; (8) how to determine test length, testing frequency, and related problems; (9) how to design and develop correlated remedial materials; (10) how to design and carry out pilot tests of mastery learning draft materials; and (11) how to revise drafts based on pilot test findings. Practical suggestions are included for authors, editors, artists, and others in the development process. (Authors/JD)