Measurement of information

摘要

This paper presents and discusses implications of a set of measures of information, within the framework of the following definition of the term: Information is that property of data (i.e., recorded symbols) which represents (and measures) effects of processing of them. As a context for this definition, the paper discusses colloquial use of the term and of other relevant terms, the historical development of measurement theories related to them, and the problems that have to this point been unresolved in reconciling colloquial and theoretical uses of them. In the definition of information, processing of data plays a central role. Four levels of processing are considered in the paper: (a) data transfer, (b) data selection, (c) data structuring, and (d) data reduction, for each, the paper defines an associated measure of the resulting amount of information and presents justification for it; each in the succession of measures generalizes from the earlier ones, involving the addition of variables that characterize the additional level of processing.