The uses and methods of four levels of evaluation which can be conducted during the development and implementation phases of computer-based instruction (CBI) programs are discussed in this paper. The levels of evaluation presented are: (1) documentation, (2) formative evaluation, (3) assessment of immediate learner effectiveness, and (4) impact evaluation. The components of the documentation level of evaluation, which include monitoring project costs, recordkeeping, and personal observation, are outlined; the processes involved in formative evaluation, including internal review and operational testing, are described; the various factors involved in the assessment of immediate learner effectiveness are summarized; and the nature of impact evaluation is discussed. A set of nine sample evaluation forms relating to different levels of evaluation and their associated methods and a 24-item bibliography accompany the text. (JL)