Terminological Variation, a Means of Identifying Research Topics from Texts

Terminological variation, a means of identifying research topics from texts Fidelia IBEKWE-SANJUAN CRISTAL-GRESEC, Stendhal University, Grenoble France and Dept. of Information & Communication IUT du Havre - B.P. 4006 - 76610 Le Havre France E-mail : fidelia@iut.univ-lehavre.fr Abstract After extracting terms from a corpus of titles and abstracts in English, syntactic variation relations are identified amongst them in order to detect research topics. Three types of syntactic variations were studied : permutation, expansion and substitution. These syntactic variations yield other relations of formal and conceptual nature. Basing on a distinction of the variation relations according to the grammatical function affected in a term - head or modifier - term variants are first clustered into connected components which are in turn clustered into classes. These classes relate two or more components through variations involving a change of head word, thus of topic. The graph obtained reveals the global organisation of research topics in the corpus. A clustering method has been built to compute such classes of research topics. Introduction The importance of terms in various natural language tasks such as automatic indexing, computer-aided translation, information retrieval and technology watch need no longer be proved. Terms are meaningful textual units used for naming concepts or objects in a given field. Past studies have focused on building term extraction tools : TERMINO (David S. & Plante P. 1991), LEXTER (Bourigault D. 1994), ACABIT (Daille 1994), FASTR (Jacquemin 1995), TERMS (Katz S.M. & Justeson T.S. 1995). Here, term extraction and the identification of syntactic variation relations are considered for topic detection. Variations are changes affecting the structure and the form of a term producing another textual unit close to the initial one e.g. dna amplification and amplification fingerprinting of dna. Variations can point to terminological evolution and thus to that of the underlying concept. Topic is used in its grammatical sense, i.e. the head word in a noun phrase. In the above term, fingerprinting is the topic (head word) and dna amplification its properties (modifiers). However, a topic cannot appear by chance in specialised litterature, so this grammatical definition needs to be backed up by empirical evidence such as recurrence of terms sharing the same head word. We constituted a test corpus of scientific abstracts and titles in English from the field of plant biotechnology making up ---29000 words. These texts covered publications made over 13 years (1981-1993). We focused on three syntactic variation types occurring frequently amongst terms : permutation, substitution and expansion (§2). Tzoukermann E. Klavans J. and Jacquemin C. (1997) extracted morpho-syntactic term variants for NLP tasks such as automatic indexing. They accounted for a wide spectrum of variation producing phenomena like the morpho-syntactic variation involving derivation in tree cutting and trees have been cut down 1. We focused for the moment on terms appearing as noun phrases (NP). Although term variants can appear as verb phrases (VP), we believe that NP variants reflect more terminological stability thus a real shift in topic (root hair --~ root hair deformation) than their …

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