From Terminologies to Classifications - the Challenge of Information Reduction

A description of a medical cases can - as any statement about reality - contain more or less information The ann of a classification is to express as much as possible with a minimum of words (classes). For this purpose the information contained in a terminology must be reduced Is such a reduction all obvious process? In this paper we examine this question by considering practical aspects arising from the task of "teaching" computers automated ICD-10 coding of diagnoses in text form. We first assess the extent of information reduction and then discuss the path along which this reduction takes place. The role and conditions of a true hierarchical structure are discussed, as well as [lie questions that stem from reduction of [lie many semantic dimensions to the single dimension of a formal hierarchy Special attention is given to the sum/summands problem, a major challenge for automated classification in practice Are medical classifications necessary at all? Just because extracting class information from termniological data is not self-evident, the classification holds information which is not otherwise available