Online research in philosophy

This paper develops a general approach to contextual reasoning in natural language processing. Drawing on the view of natural language interpretation as abduction (Hobbs et al., 1993), we propose that interpretation provides an explanation of how an utterance creates a new discourse context in which its interpreted content is both true and promi- nent. Our framework uses dynamic theories of semantics and pragmatics, formal theories of context, and models of attentional state. We describe and illustrate a Prolog implementation.

According to the thesis of semantic underdetermination, most sentences of a natural language lack a definite semantic interpretation. This thesis supports an argument against the use of natural language as an instrument of thought, based on the premise that cognition requires a semantically precise and compositional instrument. In this paper we examine several ways to construe this argument, as well as possible ways out for the cognitive view of natural language in the introspectivist version defended by Carruthers. Finally, we sketch a view of the role of language in thought as a specialized tool, showing how it avoids the consequences of semantic underdetermination.

One way of describing the enterprise of natural language semantics is by analogy with interpreted formal languages, e.g. the language of arithmetic interpreted on the natural numbers. English is then the formal language consisting of the well-formed sentences of English interpreted on the structure we happen to nd around us. The business of the natural language semanticist is to describe the correlation of the formal expressions with that structure. This paper is directed against this particular interpretation 1 of the enterprise of logical natural language semantics.

A cognitive pragmatic approach is taken to some long-standing problem cases of negation, the so-called presupposition denial cases. It is argued that a full account of the processes and levels of representation involved in their interpretation typically requires the sequential pragmatic derivation of two different propositions expressed. The first is one in which the presupposition is preserved and, following the rejection of this, the second involves the echoic (metalinguistic) use of material falling in the scope of the negation. The semantic base for these processes is the standard anti-presuppositionalist wide-scope negation. A different view, developed by Burton-Roberts (1989a, 1989b), takes presupposition to be a semantic relation encoded in natural language and so argues for a negation operator that does not cancel presuppositions. This view is shown to be flawed, in that it makes the false prediction that presupposition denial cases are semantic contradictions and it is based on too narrow a view of the role of pragmatic inferencing.

This course aims to assess the principle of compositionality (CP) and how it fits with recent developments in natural language interpretation, especially those that stress the role of context. We first try to lay down a suitable formal framework for CP, reviewing proposals by Montague, Janssen, Hendriks, Kracht and Hodges. Versions of CP of varying strength are formulated, and some recent results on the existence of compositional semantics and the (much debated) issue of the empirical import of CP discussed. Complementing CP is the notion of context which, under modern (e.g. "dynamic") conceptions, not only conditions interpretation but also is transformed during interpretation. The tension between CP and context is examined relative to problems of anaphora, presupposition, idioms and ambiguity. A somewhat un-orthodox computational application of CP is suggested, emphasizing co-inductive aspects of interpretation that cut across the divide between model-theoretic and proof-theoretic approaches, and between procedural and declarative styles.

The aim of this article is to elucidate the processes that characterize natural language interpretation. The basic hypothesis is that natural language interpretation can be characterized as an optimization problem. This innovative view on interpretation is shown to account for the crucial role of contextual information while avoiding certain well-known problems associated withcompositionality. This will become particularly clear in the context of incomplete expressions. Our approach takes as a point of departure total freedom ofinterpretation in combination with the parallel application of soft constraints on possible interpretations. These constraints can be contextual, intonational or syntactic in nature. The integration of pragmatic andsyntactic/semantic information in a system of ranked constraints is proposed to correctly derive the optimal interpretations in cases of nominal anaphorization, determiner quantification and elliptical comparatives.

We propose a novel interpretation of natural-language questions using a modal predicate logic of knowledge. Our approach brings standard model-theoretic and proof-theoretic techniques from modal logic to bear on questions. Using the former, we show that our interpretation preserves Groenendijk and Stokhof's answerhood relation, yet allows an extensional interpretation. Using the latter, we get a sound and complete proof procedure for the logic for free. Our approach is more expressive; for example, it easily treats complex questions with operators that scope over questions. We suggest a semantic criterion that restricts what natural-language questions can express. We integrate and generalize much previous work on the semantics of questions, including Beck and Sharvit's families of subquestions, non-exhaustive questions, and multi-party conversations.

Are rules processes or similarity processes the default for acquisition of grammatical knowledge during natural second language acquisition? Whereas Pothos argues similarity processes are the default in the many areas he reviews, including artificial grammar learning and first language development, I suggest, citing evidence, that in second language acquisition of grammatical morphology “rules processes” may be the default.

Notions of context for natural language interpretation are factored in terms of three processes: translation, entailment and attunement. The processes are linked by accessibility relations of the kind studied in many-dimensional modal logic, modulo complications from constraints between translation and entailment (violations in which may trigger re-attunement) and from refinement and underspecification.