NAME WordNet-SenseRelate version 0.01 OVERVIEW Selecting the correct sense of a word in a context is called word sense disambiguation (WSD). The correct sense is selected from a set of predefined senses for that word (i.e., from a dictionary). SYNOPSIS use WordNet::SenseRelate; use WordNet::QueryData; my $qd = WordNet::QueryData->new; my %options = (wordnet => $qd, measure => 'WordNet::Similarity::lesk' ); my $wsd = WordNet::SenseRelate->new (%options); my @words = qw/when in the course of human events/; my @res = $wsd->disambiguate (window => 2, tagged => 0, scheme => 'normal', context => [@words], ); print join (' ', @res), "\n"; DESCRIPTION Words can have multiple meanings or senses. For example, the word *glass* in WordNet [1] has seven senses as a noun and five senses as a verb. Glass can mean a clear solid, a container for drinking, the quantity a drinking container will hold, etc. WSD is the process of selecting the correct sense of a word when that word occurs in a specific context. For example, in the sentence, "the window is made of glass", the correct sense of glass is the first sense, a clear solid. WordNet::SenseRelate implements an extension of the algorithm described by Pedersen, Banerjee, and Patwardhan [2]. This implementation is similar to the original SenseRelate package. The original SenseRelate was intended for a "lexical sample" situation where the goal is to disambiguate only one word (specified by markup tags) in a given context. The goal of WordNet::SenseRelate is to disambiguate every word in a context or document. The output will be in the form word#part_of_speech#sense_number. The part of speech will be one of 'n' for noun, 'v' for verb, 'a' for adjective, or 'r' for adverb. Words from other parts of speech are not disambiguated and are not found in WordNet. The sense number will be a WordNet sense number. WordNet sense numbers are assigned by frequency, so sense 1 of a word is more common than sense 2, etc. Sometimes when a word is disambiguated, a "different" but synonymous word will be found in the output. This is not a bug, but is a consequence of how WordNet works. The word sense returned will always be the first word sense in a synset (synonym set) to which the original word belongs. Algorithm for each word w in input disambiguate-single-word (w) disambiguate-single-word for each sense s_ti of target word t let socre_i = 0 for each word w_j in context window next if j = t for each sense s_jk of w_j temp-score_k = relatedness (s_ti, s_jk) best-score = max temp-score if best-score > threshold score_i = score_i + best-score return i s.t. score_i > score_j for all j in {s_t0, ..., s_tN} The Context Window The size of the context window can be specified by the user. A context window of size 3 means that the 3 words to the left and the 3 words to the right of the target word will be in the context window; however, the algorithm will expand the context window so that the 3 words to the left will be words known to WordNet. For example, if the word 'the', occurs in the context window to the left of the target word, then the window will be expanded by one word to the left. Note that the context window will only include words in the same sentence as the target word. If, for example, the target word is the first word in the sentence, then there will be no words to left of the target word in the context window. SEE ALSO WordNet::SenseRelate(3) wsd.pl(1) AUTHORS Jason Michelizzi Ted Pedersen COPYRIGHT AND LICENSE Copyright (C) 2004 by Jason Michelizzi and Ted Pedersen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. REFERENCES 1. Christiane Fellbaum. 1998. WordNet: an Electronic Lexical Database. MIT Press. 2. Ted Pedersen, Satanjeev Banerjee, and Siddharth Patwardhan. 2003. Maximizing Semantic Relatedness to Perform Word Sense Disambiguation.