This paper reviews work that has been done on defining and measuring conceptual structures of critical flight information in Air Force fighter pilots. Individuals with widely varying flight experience were tested. Cognitive structures were defined by analytic procedures; e.g., Multidimensional Scaling (MDS) and General Weighted Networks (GWN). The MDS analysis showed that the level of flying experience can be predicted from the pilot's conceptual structure. The GWN analysis led to the identification of specific points of agreement and disagreement in the conceptual organization of novice and expert pilots. Pilots do have measurable cognitive structures for organizing flight- related information. These structures are measurably different for individuals with different flight experience. The techniques employed in the research produce descriptions of conceptual structure that may have applications in the training program of fighter pilots and in assessing individual differences in the development of appropriate conceptual structures.