Recent research has shown that mental models are constructs for understanding tactical thinking that can also guide the development of training and training evaluation (Ross, McHugh, Harris & Pliske, 2003). In the context of developing an Intelligent Tutoring System (ITS) for teaching tactical thinking skills, we examined themes underlying tactical expertise developed in earlier research (Deckert, Entin, Entin, MacMillan, & Serfaty, 1994; Lussier, 1998). They are (1) Keep a Focus on the Mission and Higher Headquarters' Intent; (2) Model a Thinking Enemy; (3) Consider Effects of Terrain; (4) Know and Use All Assets Available; (5) Consider Timing; (6) See the Big Picture; (7) Consider Contingencies and Remain Flexible; and, (8) Visualize the Battlefield. During the ITS development, we observed 24 instructional sessions in which expert tacticians provided one-on-one tutoring to novices during scenario-based training. One of our research goals was to refine our understanding of how the themes are developed and used. In our analysis of the tutorial session transcripts, we documented developmental stages within each theme, and described the interactions between themes, i.e., the sequence in which the themes are acquired and used as expertise develops. In a subsequent project, we developed concepts of training measurement within the framework of macrocognition. For one measure, we used the themes to guide our development of cognitively based Behaviorally Anchored Rating Scale (BARS) that could assess mental models. As we developed the BARS, we concluded that some of the themes represent mental models and some represent how mental models are used in the performance of tactical thinking. Future research will focus on validation of the macrocognition functions and processes and their measurement.