Aggregate statistical data: models for their representation

The paper gives a review of a number of data models for aggregate statistical data which have appeared in the computer science literature in the last ten years.After a brief introduction to the data model in general, the fundamental concepts of statistical data are introduced. These are called statistical objects because they are complex data structures (vectors, matrices, relations, time series, etc) which may have different possible representations (e.g. tables, relations, vectors, pie-charts, bar-charts, graphs, and so on). For this reason a statistical object is defined by two different types of attribute (a summary attribute, with its own summary type and with its own instances, called summary data, and the set of category attributes, which describe the summary attribute). Some conceptual models of statistical data (CSM, SDM4S), some semantic models of statistical data (SCM, SAM*, OSAM*), and some graphical models of statistical data (SUBJECT, GRASS, STORM) are also discussed.