Paul R. Yarnold

Optimal Data Analysis, LLC

As concerns the existence of statistically reliable enumerated-optimal classification tree analysis (EO-CTA) model(s) for a given application, possible alternative analytic outcomes are: no EO-CTA model exists; one model exists; or a descendant family (DF) that consists of two or more models exists. Models in a DF maximize ESS for unique partitions of the sample, and the model with the lowest observed D statistic is the globally-optimal CTA (GO-CTA) model for the application. The brute-force method of identifying a DF involves obtaining an initial EO-CTA model without specifying minimum end¬point sample size, then applying the minimum denominator selection algorithm (MDSA) to the initial model. A more efficient methodology for obtaining the GO-CTA model involves including only the attribute subset identified using structural decomposition analysis (SDA). The DF for the SDA attribute subset differs from the DF identified for the entire attribute set because the DF is data-specific. These methods are illustrated for an application using rated aspects of nursing and physician care to discriminate 1,045 very satisfied vs. 671 satisfied Emergency Department (ED) patients.