Precision-Recall-Optimization in Learning Vector Quantization Classifiers for Improved Medical Classification Systems

Classification and decision systems in data analysis are mostly based on accuracy optimization. This criterion is only a conditional informative value if the data are imbalanced or false positive/negative decisions cause different costs. Therefore more sophisticated statistical quality measures are favored in medicine, like precision, recall etc.. Otherwise, most classification approaches in machine learning are designed for accuracy optimization. In this paper we consider variants of learning vector quantizers (LVQs) explicitly optimizing those advanced statistical quality measures while keeping the basic intuitive ingredients of these classifiers, which are the prototype based principle and the Hebbian learning. In particular we focus in this contribution particularly to precision and recall as important measures for use in medical applications. We investigate these problems in terms of precision-recall curves as well as receiver-operating characteristic (ROC) curves well-known in statistical classification and test analysis. With the underlying more general framework, we provide a principled alternatives traditional classifiers, such that a closer connection to statistical classification analysis can be drawn.