"Research on cognitive architectures varies widely in the degree to which it attempts to match psychological data. ACT-R (Anderson & Lebiere, 1998) and EPIC (Kieras & Meyer, 1997) aim for quantitative fits to reaction time and error data, whereas Prodigy (Minton et al., 1989) incorporates selected mechanisms like means-ends analysis but otherwise makes little contact with human behavior. Architectures like Soar (Laird, Newell, & Rosenbloom, 1987; Newell, 1990) and Icarus (Langley & Choi, in press; Langley & Rogers, 2005) take a middle position, drawing on many psychological ideas but also emphasizing their strength as flexible AI systems. What they hold in common is an acknowledgement of their debt to theoretical concepts from cognitive psychology and a concern with the same intellectual abilities as humans."