Abstract

Introduction

The GL claims to be a general theory of the lexicon. Pustejovsky identifies “the creative uses of words in novel contexts” (Pustejovsky, 1995, p. 1) as one of two central issues which GL addresses, where other formal theories have remained silent. He asserts as a principle that “a clear notion of semantic well-formedness will be necessary in order to characterise a theory of possible word meaning“ (ibid, p. 6) and identifies a generative lexicon as a framework in which a core set of word senses is used to generate a larger set, according to a set of generative devices. Most work in the GL tradition has been concerned to identify and formally specify those devices.

What is the meaning of a word? How can the few hundreds of thousands of words we know be used to construct the many millions of utterances we make and understand in a lifetime? It would appear we need more words than we have available to us, if classical wisdom on this subject is to be believed. The subject, of course, is lexical semantics, and classical wisdom can often be wrong. This field has undergone a radical shift in recent years, in large part because of two developments. First, formal frameworks for word meaning have been developed that greatly simplify the description of lexical classes and their properties. Second, we have at our disposal new compositional techniques that allow us to view word meaning as an integral part of the overall process of semantic interpretation. These and other factors have made the issues relating to ‘the meaning of a word’ some of the most central questions being addressed in the field of linguistics today. In fact, some classic issues have resurfaced with new data and arguments, such as the debate over analyticity and semantic knowledge, as well as the evidence of a distinction (or nondistinction) between lexical and world knowledge.

Waismann (1951) argued for what he called the ‘open texturedness’ of terms. Although he was mainly interested in how the notion applies to the nonexhaustive nature of material object statements and the absence of conclusive verification conditions, there is another sense in which this is an interesting property of language and language use; the infinite variability of reference in language is the direct product of the essential incompleteness of terms and their composition.

Abstract

Introduction

A certain metaphysical thesis about meaning that we will call Informational Role Semantics (IRS) is accepted practically universally in linguistics, philosophy, and the cognitive sciences: the meaning (or content, or “sense”) of a linguistic expression is constituted, at least in part, by at least some of its inferential relations. This idea is hard to state precisely, both because notions like metaphysical constitution are moot and, more importantly, because different versions of IRS take different views on whether there are constituents of meaning other than inferential role, and on which of the inferences an expression occurs in are meaning constitutive. Some of these issues will presently concern us, but for now it will do just to mention such familiar claims as that: it's part and parcel of “dog” meaning ‘dog’ that the inference from “x is a dog” to “x is an animal” is valid; it's part and parcel of “boil” meaning ‘boil’ that the inference from “x boiled y” to “y boiled” is valid; it's part and parcel of “kill” meaning ‘kill’ that the inference from “x killed y” to “y died” is valid; and so on (see Cruse, 1986, Chap. 1 and passim).

The goal of this part of the volume is best explained by the recent interest in evaluating which lexical semantics resources are available for Natural Language Processing (NLP) and whether a methodology can be established for building large-scale semantic knowledge-bases.

The papers address the topic of understanding and structuring word meaning from the particular perspective of building NLP systems. Here, the problem of how to represent word meaning has fairly strict requirements: It affects the choice of particular data structure as well as the specific architectural requirements for a computational lexicon.

All of the contributions in this section present practical questions and dilemmas that are not usually faced in theoretical research. The first issue is one of methodology: Can existing semantic resources (viz. ontologies) be reproduced by identifying a consistent set of criteria? This is an important question, because a positive answer would mean that we have achieved an understanding of how to model conceptual knowledge independently of domains and people's intuitions.

The second issue is whether existing lexical semantics frameworks provide the basis for developing a large-scale resource on systematic grounds. Although related to previous question this problem is also relevant to the notion of “scalability.” In other words, if a particular framework makes certain claims about how meaning should be structured to account for a limited number of linguistic facts, is the suggested structuring sufficiently general to cover a large corpus? Furthermore, were that corpus to become even larger, would the lexicon scale up easily to cover the newer data? More or less explicit answers are found in the different contributions.

Abstract

Direct Causation and Event Coreference

The Notion of Direct Causation

It is well known that causal relations can be of different kinds. Among them, the direct causal relation is often mentioned in the literature and among others, by Fodor (1970) and Schank (1975). In the line of these works, I define the notion of a direct causation on conceptual grounds as follows: the result is a physical change of state for an object Y, the cause is an action performed by a human agent X, the action is the direct cause of the change of state.

Abstract

Introduction

Chomsky began to mention the creative aspect of language use in the early 1960s; his 1964 Current Issues discusses it. In 1966, Cartesian Linguistics takes it up in detail. At the end of the 1950s he had read extensively in the works of Descartes, Cudworth, Humboldt, and others in the seventeenth to mid-nineteenth centuries “Cartesian linguistics” tradition, and they provided a framework for articulating these ideas. Arguably, though, they were implicit in his review of Skinner and even in The Logical Structure of Linguistic Theory (ca. 1955). The creative aspect observations, along with the poverty of stimulus observations, offer a set of facts with which his and – he holds – any science of language must contend. However, he thinks that the lessons of the creative aspect observations in particular are often ignored, especially in dealing with semantic issues such as truth and reference, meaning and content. He may be right. I review the creativity observations and discuss some of their implications and suggestions for a semantic theory of the lexicon. In their light, I discuss briefly James Pustejovsky's different approach.

Abstract

Introduction

The development of formal frameworks for computational lexical semantics should respond to two needs: capturing the richness of language as revealed in both meaning variation and systematic polysemy, and providing a viable and testable model for building large-scale lexical resources for natural language processing.

In this paper, we address these topics from the dual perspective of theory and applications. The theoretical aspect motivates a generative framework for structuring and generating concepts. The practical aspect focuses on the implementation of the GL-based framework within the EU-sponsored SIMPLE project, which involves the development of harmonized large-scale semantic lexicons (10,000 word senses) for twelve different languages.

This quote from Patrick Hanks reflects very closely the spirit of this volume that tackles the relation between word meaning and human linguistic creativity. We are interested in pursuing the view that words are rich repositories of semantic information that people use to talk about the world in a potentially infinite number of ways. Our goal is to tackle the essence of words insofar as they provide a window onto human cognition and the compositional nature of thought. It is thus imperative that a theory of language addresses how lexical items contribute to the peculiar human ability that goes under the label of “linguistic creativity.”

It is undeniable that words have “meanings” that go above and beyond the scope of linguistic research: They often carry the weight of a person's own experience. We are not aiming at exploring the unexplorable, but in proving that, given an appropriate set of methodological tools, a formal modeling of word meaning and linguistic creativity can be achieved. Linguistic creativity is a “generative” ability to extend the expressive possibilities of language in a potentially infinite number of ways. From the perspective of the lexicon (i.e., word meaning), it is the ability to give new meanings to words beyond their literal use.

As such, the overall task follows the strategy of contemporary generative syntax, which has achieved a basic understanding of how speakers produce and understand novel utterances and has brought simplicity to the great complexity underlying the syntactic structure of sentences.

The contributions in this section are centered around a set of common themes:

1. developing a theoretical vocabulary sufficiently rich to understand how word meanings compose;

2. developing and motivating frameworks for lexical semantics with explanatory force;

3. analyzing cross-linguistic data for achieving linguistically independent models.

Although each contribution approaches the problems from different angles and different data sets, they all highlight the richness of the information carried by words in context. The real challenge, as it emerges from the papers, is whether it is possible to establish a clear boundary between people's words and people's worlds or experiences. The goal is to understand whether there is a level of representation that is independent of specific contextual variations, while accounting for the novel use of words in different contexts.

The authors reach different conclusions: some reject structured representations of lexical information, others show that it is precisely in the structuring of the lexicon that we can achieve an understanding of how meaning changes in context.

The first paper by James Pustejovsky presents recent developments in GL, focusing on the role of qualia structure as a syntax for creating new concepts. The paper addresses fundamental questions on the well-formedness of concepts, the combinatorial possibilities within a generative mental lexicon, and how these principles are motivated by linguistic evidence.

The contribution by Jacques Jayez focuses on the meaning variations of the French verbs “suggerer” (suggest) and “attendre” (wait).

Abstract

Introduction

Recent work about the relation between lexical items, context, and interpretation has highlighted two notions of underspecification (see van Deemter and Peters, 1996 for various points of view). In some approaches, underspecification amounts to code ambiguities in an efficient way, to avoid carrying a set of alternatives during the interpretation process (Reyle, 1995). In the domain of the lexicon, underspecification sometimes takes the form of information enrichment.

Introduction

Metaphor, and the distinction between the figurative and the literal uses of language, have puzzled philosophers and linguists at least since Aristotle. The puzzle can be stated in the following, rough, form: How can words in certain configurations mean something different from what they mean in their literal use, prescribed by the rules of the language, and at the same time convey significant insights into what we, in a given context, take as parts of reality? In order to appreciate the force of the question we must separate the metaphorical meanings from the new literal meanings that an individual, or a group, might introduce into a language, such as parenting, or critiquing. Such innovations are extensions of literal language, not metaphors. Metaphors rest on rules of language, but also violate them. They do not describe reality directly. Thus, the true/false dichotomy does not apply to them without qualifications. An adequate theory of metaphor should explain this unique position of metaphoric meaning. To expand on this a little, this essay proposes that a theory of metaphoric meaning should account for the following list of facts or intuitions.

1. (i) Metaphors give us new meanings and a deepened understanding of the objects of our descriptions or reasoning.

2. (ii) Metaphors can have aesthetic value.

3. (iii) At some stage, a subjective element enters into the interpretation of metaphors. This element is creative insofar as it goes beyond what is given by the rules of language but it presupposes and rests on such rules.

4. […]

Abstract

Language and Category Formation

Since the early days of artificial intelligence, researchers have struggled to find a satisfactory definition for category or concept, one which both meets formal demands on soundness and completeness, and practical demands on relevance to real-world tasks of classification. One goal is usually sacrificed in the hope of achieving the other, where the results are muddled with good intentions but poor methodology.