Abstract: A knowledge tree building system iteratively partitions a database of case records into a tree of conceptually meaningful clusters. Each cluster is automatically assigned a unique conceptual meaning in accordance with its unique pattern of typicality and exceptionality within the knowledge tree; no prior domain-dependent knowledge is required. The system fully utilizes all available quantitative and qualitative case record data. Knowledge trees built by the system are particularly well suited for artificial intelligence applications such as pattern classification and nonmonotonic reasoning.

Abstract: A method for testing the visual system to detect the presence of disease, and to distinguish disease which has degraded the linear visual pathway from disease degrading the nonlinear visual pathway in a manner which is substantially independent of the stimulus applied to the eye and the connection of the instrumentation to the patient being tested. Three light sources having their amplitude varied at different frequencies stimulate the eye. The response evoked in the brain is detected and Fourier analyzed. The amplitude of selected Fourier components are detected and used to compute a ratio which removes the dependence upon the factors stated above. The Fourier component amplitude factors are selected so that the number of factors in the numerator of the ratio is equal to the number in the denominator and the sum of the orders of the factors in the numerator are equal to the sum of the orders in the denominator.