WordNet::Similarity::vector_pairs 1.04

WordNet::Similarity::vector_pairs is a Perl module for computing semantic relatedness of word senses using second order co-occurrence vectors of glosses of the word senses.

SYNOPSIS

use WordNet::Similarity::vector_pairs;

use WordNet::QueryData;

my $wn = WordNet::QueryData->new();

my $vector_pairs = WordNet::Similarity::vector_pairs->new($wn);

my $value = $vector_pairs->getRelatedness("car#n#1", "bus#n#2");

($error, $errorString) = $vector_pairs->getError();

die "$errorStringn" if($error);

print "car (sense 1) <-> bus (sense 2) = $valuen";

Schütze (1998) creates what he calls context vectors (second order co-occurrence vectors) of pieces of text for the purpose of Word Sense Discrimination. This idea is adopted by Patwardhan and Pedersen to represent the word senses by second-order co-occurrence vectors of their dictionary (WordNet) definitions. The relatedness of two senses is then computed as the cosine of their representative gloss vectors.
A concept is represented by its own gloss, as well as the glosses of the neighboring senses as specified in the vector-relation.dat file. Each gloss is converted into a second order vector by replacing the words in the gloss with co-occurrence vectors for those words. The overall measure of relatedness between two concepts is determined by taking the pairwise cosines between these expanded glosses. If vector-relation.dat consists of:

example-example
glos-glos
hypo-hypo

then three pairwise cosine measurements are made to determine the relatedness of concepts A and B. The examples found in the glosses of A and B are expanded and measured, then the glosses themselves are expanded and measured, and then the hyponyms of A and B are expanded and measured. Then, the values of these three pairwise measures are summed to create the overall relatedness score.

$measure->initialize($file)

Overrides the initialize method in the parent class (GlossFinder.pm). This method essentially initializes the measure for use.

Parameters: $file -- configuration file.

Returns: none.

$measure->traceOptions()

This method is internally called to determine the extra options specified by this measure (apart from the default options specified in the WordNet::Similarity base class).
Parameters: none.

Returns: none.

$vector_pairs->getRelatedness

Computes the relatedness of two word senses using the Vector Algorithm.

Parameters: two word senses in "word#pos#sense" format.
Returns: Unless a problem occurs, the return value is the relatedness score, which is greater-than or equal-to 0. If an error occurs, then the error level is set to non-zero and an error string is created (see the description of getError()).