tailieunhanh - Báo cáo khoa học: "Non-Literal Word Sense Identification Through Semantic Network Path Schemata"

When computer programs disambiguate words in a sentence, they often encounter non-literal or novel usages not included in their lexicon. In a recent study, Georgia Green (personal communication) estimated that 17% to 20% of the content word senses encountered in various types of normal English text are not fisted in the dictionary. While these novel word senses are generally valid, they occur in such great numbers, and with such little individual frequency that it is impractical to explicity include them all within the lexicon. . | Non-Literal Word Sense Identification Through Semantic Network Path Schemata Eric Iverson Stephen Helmreich Computing Research Lab and Computer Science Department Box 3OOO1 3CRL New Mexico State University Las Croces. NM 88003-0001 When computer programs disambiguate words in a sentence they often encounter non-literal or novel usages not included in then lexicon. In a recent study Georgia Green personal communication estimated that 17 to 20 of the content word senses encountered in various types of normal English text are not listed in the dictionary. While these novel word senses are generally valid they occur in such great numbers and with such little individual frequency that it is impractical to explicitly include them all within the lexicon. Instead mechanisms are needed which can derive novel senses from existing ones thus allowing a program to recognize a significant set of potential word senses while keeping its lexicon within a reasonable size. Spreading activation is a mechanism that allows us to do this. Here the program follows paths from existing word senses stored in a semantic network to other closely associated word senses. By examining tile shape of the resultant path we can determine the relationship between the senses contained in the path thus deriving novel composite meanings not contained within any of the original lexical entries. This process is similar to the spreading activation and marker passing techniques of Hirst 1988 Chamiak 1986 and Norvig 1989 and is embodied in the Prolog program metallel based on Pass program meta5 Fass 1988 . Metallel s lexicon is written as a series of sense frames each containing information about a particular word sense. A sense frame can be broken into two main parts genera and differentiae. Genera are the genus terms that function as the ancestors of a word sense. Differentiae denote the qualities that distinguish a particular sense from other senses of the same genus. Differentiae can be broken down into .