To meet evolving operational challenges, we must leverage new strategies to train officers "how to think," as well as "what to think," preparing them to succeed in the face of unexpected events. This paper describes a model used for training adaptive battlefield thinking and the experimental program of instruction to implement and test that model with officers at the US Army Command and General Staff College (CGSC). In a recent project—Army Experiment 6 (AE6)—the challenge to provide a training strategy for adaptive thinking was met by a cooperative effort between the US Army Research Laboratory (ARL) and the US Army Research Institute (ARI). Each organization initially responded to the requirement with proposed approaches that at first glance seemed to be diametrically opposed. The operational question became whether we could integrate the approaches to define, train and measure adaptive performance. The two approaches proposed were a Constructivist Advanced Learning model and the Deliberate Practice model. The Constructivist model, an ecological approach to training, and Deliberate Practice, based on a Behaviorist orientation, were surprisingly complementary. A synthesized approach was developed and implemented as the "Adaptive Thinking Program of Instruction" (AT POI) to train brigade staff decisionmaking during execution. Eleven Majors from the Advanced Tactics elective, A308, at the CGSC Officer's Course participated in the experimental course in the spring of 1999. The students participated in exercises with a team of highly experienced military experts acting as mentors. The first part of the instruction concentrated on creating a multi-dimensional understanding of the battlefield and actually used a more tradition instructional approach. The second portion of the instruction was in the form of a capstone exercise. It centered on intense deliberate practice of cognitive skills in an environment designed in accordance with the Constructivist model and the Deliberate Practice model. The process to guide the practice was based on the Constructivist model, and it was also congruent with the Deliberate Practice model. Student insight into battlefield situations was supported in both parts of the instruction by use of a consistent set of themes that have been shown to represent expert perception of battlefield situations, and by simulations to enact and display developing situations under discussion. Performance was compared with that of similar students in a control group who did not receive the special training, but who completed the existing advanced tactics elective course during the first half of the AT POI and participated in a traditionally structured capstone exercise during the second half. Performance measurement, consisting of a structured method for eliciting situation assessments, was conducted pre- and post-training for the first half of the course and pre- and post-training for the second half of the course. The performance instrument was adapted from an ARI experimental assessment instrument. Subject matter expert and student assessments of the training were also gathered by means of surveys and interviews. Students who completed the AT POI were found to perform significantly better at adaptive tactical thinking. Better performance was found after the second half of the course only—the intense practice portion. The first half of the course, more traditional in nature, did not produce measurable gains in adaptive thinking. We conclude the paper with recommendations for maintenance of model integrity as this approach is disseminated and with reference to further research and development needed for assessment of adaptive thinking skills.