ABSTRACT
Underlying this chapter is the thesis that any foundational work on geographic information science, with the emphasis on information, should draw on general theories of information science. In particular, discussions of communication of geographic information need to be founded in the general work of information scientists on this topic. An example of a fundamental question that we would like to be able to begin to answer is “Given two data sources, is the information contained in one equal, greater, less than, or incomparable, with the other?”. To approach questions of this sort, the notion of information ‘value’ becomes important. To discuss the question of the value of geographic information, Michael Goodchild (this volume) began with the commodity metaphor, where the value of geographic information is viewed in a similar way to the value of a barrel of crude oil. The issue then becomes how value is assessed. Simpleminded measures based upon quantities of data are clearly irrelevant, as the relationship between data and information is indirect. Goodchild goes on to argue for a measurement of value that takes account of the semantics of the information. This chapter takes the process one step further, beginning with the observation that the value of information also depends critically on the requirements and purposes of the recipient, which is part of the context in which the information is requested and received. To illustrate these points, consider the information conveyed by the statement “The window is unlocked”. The value of this information will be greater for a burglar investigating the potential of a house in the neighborhood than for a casual passer-by, although the semantics in both cases could be the same. The key concept here is relevance, where relevant information is “information that modifies and improves an overall representation of the world” (Sperber and Wilson, 1995). The relevance of an item of information will depend not only on its syntactic form and semantic content, but also on the context in which it is transmitted and received.
