Defining in precise detail the diagnostic clues used by histopathologists to arrive at a diagnosis is a difficult process; however, better analytic understanding of this process is a prerequisite for the design of diagnostic expert systems. Such systems offer the potential for consistency and setting standards in the diagnostic evaluation of difficult situations. Diagnostic clues as offered by the image represent two-dimensional information. Their description is entered into the knowledge base of an aspect system, however, in the form of a description, which is one-dimensional. Preserving all of the two-dimensional dependence structure in this conversion is a fundamental problem. Use of the description to generate simulated imagery tests whether or not the two-dimensional dependence structure of a given tissue architecture has been adequately represented in the analytic description. This analytic description would then be entered into the knowledge base of an expert system.