Elsnet 97 Summer School Lexicon Development for Language and Speech Processing Draft Course Materials Computational Lexicography for Speech and Language 1.2 Lexical Resources 1.4 Lexical Databases and System Lexica

Contents 1 Aspects of lexicography 1 1. Bibliographical references 97 1 Aspects of lexicography This collection of course materials borrows from various materials, partly published and partly unpublished course materials. It is heterogenous, uneven, and currently in very rough shape, but contains a variety of diierent kinds of material relevant to spoken language lexicography. The collection starts with an overview of spoken language lexica and why resources are needed, following this with a review of types of lexical information at diierent levels of linguistic analysis and a chapter on lexical representation and inference. Two practical chapters cover elementary lexical databases and UNIX tools in and around lexicography. 1.1 System lexica Both written and spoken language systems, separately and in integrated form such as in dictation software, are becoming increasingly versatile, and a central task in developing such a system is the collation of lexical information. Lexical information is required both as a means of characterising properties of words in a spoken language corpus in a lexical database or knowledge base, and for the development of practically all system components. In related areas such as natural language processing (NLP) and computational and theoretical linguistics, the lexicon has come to play an increasingly central role. The lexicon of a spoken language system may be designed for broad or narrow coverage, for speciic applications, with a particular kind of organisation, and optimised for a speciic strategy of lexical search. Since the construction of a lexicon is a highly labour-intensive and thus also error-prone job, a prime requirement is for formalising lexical representations and automating lexicon development as far as possible, and in re-using lexical resources from existing applications in new developments. The main object of this chapter is to provide a framework for relating such concepts to each other and for the formulation of recommendations for development and use of lexica for spoken language systems. In this introductory section, some basic concepts connected with the use and structure of lexica in spoken language systems are outlined. In the following sections, speciic dimensions of spoken language lexica are discussed in more detail. Particular attention is paid to lexical properties related to innectional morphology, which is far more important for many other languages than it is for English, and other aspects of morphology which are important for the treatment of out-of-vocabulary words. Discussion is restricted to spoken language lexica as system development resources; non-electronic lexica …