Diagnostic Rules for Qualitative Variables with Interactions
N. Victor, Hans Joachim Trampisch, R. ZENTGRAF · Methods of Information in Medicine · 1974
An allocation rule for qualitative variables is derived which permits taking into account s-th order interactions (Lancaster’s definition is used). A formula is given using only the relative frequencies of the (s+1)-dimensional marginals for the estimation of the cell probabilities. In contrast to other procedures (e.g. the log-linear-model), the method is practicable for a large number of symptoms, too, and the estimates of the parameters of the allocation rule are stable even if samples of relatively small size are used. For the examination of the practicability of the method, two modular programs were written which permit the estimation of the parameters of the model and the expectations of the error rates. The modules are designed in a way which permits the implementation in a sequential diagnostic process.