The DVC project: Disambiguation of Verbs by Collocation ____ an introduction to the linguistic theory of norms and exploitations Patrick Hanks Research Institute of Information and Language Processing, University of Wolverhampton 1

Words are very ambiguous; dictionaries are misleading In any dictionary, more than one sense is usually given for each word. –Often, many senses. –For example, in MWALED (Merriam Websters’ Advanced Learner’s English Dictionary) the verb blow has 12 senses, plus 6 subsenses, plus 7 phrasal verbs (each with between 1 and 6 senses), plus 15 idiomatic phrases. –The noun is even more complicated. Dictionaries do not tell the user (a learner or a programmer) how to distinguish one sense of a word from another. WSD (word sense disambiguation) projects in NLP, using dictionaries, have failed, according to leaders in the field (e.g. Ide and Wilks 2006). 2

Phraseological patterns of word use Most utterances consists of words used in familiar patterns, e.g.: –The wind was blowing from the east; –the wind blew the napkin off the table; –the referee blew his whistle for the end of the match; –he blew his nose. –They blew up the bridge; –the bridge blew up. These are examples of phraseological ‘norms’ associated with blow. Unconsciously, ordinary language users repeat the same norms (patterns) over and over again, with minor variations in the various slots in the patterns. –e.g. ‘east’ alternates with ‘west’, ‘north’, ‘south’, etc. 3

Patterns are unambiguous Unlike words, patterns are unambiguous. ‘He blew up a bridge’ and ‘He blew up a balloon’ have quite distinct, unambiguous meanings –even though the words blow, bridge, and balloon can all be ambiguous when taken in isolation, out of context. –The verb is the pivot of the clause. –Each verb is associated with one or more stereotypical phraseological patterns. For NLP and language teaching alike, there is a great need for a dictionary or inventory of normal phraseological patterns. A pattern is a statistical probability, not a cut-and-dried certainty. The aim must be to inventorize all normal usage, not all possible usage. 4

Norms and exploitations The DVC project at RIILP is developing a method (Corpus Pattern Analysis) for identifying and building an inventory of prototypical phraseological norms. Each pattern consists of a syntagmatic structure plus lexical sets of collocations. Understanding meaning depends on matching the wording of an actual utterance with a pattern. –Best match wins! Speakers and writers sometimes exploit norms in various ways, for example to create new metaphors. The DVC project is also studying the rules governing exploitations of phraseological norms. 5