Historical remarks
Contextual reasoning in AIThe notion of context is widely studied in different areas of artificial intelligence (AI). We refer the reader, who wants to know more about the work on the formalisation of context in AI, to [Akman and Surav, 1996].Perhaps the first reference to context in AI can be traced back to R. Weyhrauch and his work on mechanising logical theories in the interactive theorem prover FOL [Weyhrauch, 1980]. However, it became a popular issue only in the late 1980s, when J. McCarthy proposed to formalise context as a possible solution to the problem of generality:
In the same years, D. Lenat and R. Guha introduced an explicit mechanism of contexts in the CYC common sense knowledge base [Lenat, 1995]. Guha - under McCarthy's supervision - proposed a logic of context in his Ph.D. dissertation [Guha, 1991]. In this work, several and important concepts (such as the formula Ist(c,p), lifting, entering and exiting contexts) were introduced and formalised. J. McCarthy further refined his ideas in his paper Notes on Formalizing Contexts [McCarthy, 1993]. A logic of context, based on McCarthy's ideas, was proposed by S. Buvac and his co-authors in the mid 1990's [Buvac, 1993, Buvac, 1996]. Although J. McCarthy supervised the work of his Ph.D. student, he never committed himself to Buvac's logic of context, peraphs for the strong modal flavor of such a logic. F. Giunchiglia was the first to shift the focus explicitly from context to contextual reasoning
in his 1993 paper on Contextual Reasoning [Giunchiglia, 1993]. His main motivation was the problem of locality, namely the problem of modelling reasoning which uses only a subset of what reasoners actually know about the world. The proposed framework, called Multi-Context Systems, was then applied to formalise intensional contexts, in particular belief contexts.Coherently with the proposals of J. McCarthy and F. Giunchiglia, formal logics of contexts have been applied to AI related topics.
Contextual reasoning in philosophy of science and in cognitive scienceThe interest in context is not limited to AI. On the contrary, it is discussed and used in various disciplines that are concerned with a theory of representation.
In philosophy of language, the notion of
pragmatic context has been used to provide a semantics to
indexical (demonstrative) languages at least since
J. Bar-Hillel's seminal paper on indexical expressions
[Bar-Hillel,
1954].
Almost twenty years later, D. Kaplan
published on the Journal of Philosophical Logic his
well-known formalisation of a logic of demonstratives
[Kaplan, 1978]. A broader philosophical approach to context was proposed and developed by J. Perry in his papers on indexicals and demonstratives, see [Perry, 1997]. Another approach, based on situation semantics, was pursued by J. Barwise and others [Barwise, 1986; Surav and Akman, 1995]. Recently, R. Thomason has started working on a type theoretic foundation of context [Thomason, 1999].
In cognitive science, many authors have proposed
theories of mental representation where mental contents
are thought of as partitioned into multiple contexts (also
called spaces [Dinsmore, 1991],
mental spaces [Fauconnier,
1985], etc.).
Contextual reasoning in other disciplinesWe only want to mention here that the notion of context is very important for other disciplines such as pragmatics [Givon, 1989], linguistics [Fauconnier, 1985], integration of heterogeneous knowledge and data bases [Farquhar et al., 1995, Mylopoulos and Motschnig-Pitrik, 1995, Ghidini and Serafini, 1998]. (see [Bouquet et al., 1999] for a recent collection of interdisciplinary papers on context).
Is there a theory of contextual reasoning?
Despite this large amount of work, we must admit that we
are very far from a generally accepted theory of
contextual reasoning. Even if we restrict the focus to
theories of representation and language, the definitions
of context that can be found in the literature range from
`[. . . ] a location - time, place, and possible world - at which a sentence is said' [Lewis, 1980] `[. . . ] a psychological construct, a subset of the hearer's assumptions about the world' [Sperber and Wilson, 1986] |