As part of a broad effort to improve the effectiveness and efficiency of embedded training environments, research was conducted using a Naval Tactical Data System (NTDS) console emulator. Objectives were to: (1) develop methodological guidelines for specifying the instructional content of training exercises to be embedded in NTDS consoles; (2) develop a formal procedure for sequencing the presentation of these training exercises based on the trainee's history of performance; and (3) evaluate the training gain achieved by adding these instructional dimensions. Forty-eight enlisted Navy students participated in this research. Results indicate that the cognitive engineering strategy used provided a powerful methodology for increasing the effectiveness of computer-based training, especially for procedural information. Subjects with the adaptive version improved performance by 44% after only 10 minutes of additional lesson time. Results also show that adaptive exercise sequencing increases the efficiency and effectiveness of the computer-based training. The sequence in which the exercises were presented had an effect on performance. An adaptive sequencing heuristic that takes into account the existing knowledge of the trainee is presented. Fifteen figures and 10 tables present study data. (SLD)