A Statistical Analysis of Morphemes in Japanese Terminology

A Statistical Analysis of Morphemes in Japanese Terminology Kyo KAGEURA National Center for Science Information Systems 3-29-10tsuka, Bunkyo-ku, Tokyo, 112-8640 Japan E-Mail: kyo@rd.nacsis.ac.jp Abstract In this paper I will report the result of a quan- titative analysis of the dynamics of the con- stituent elements of Japanese terminology. In Japanese technical terms, the linguistic contri- bution of morphemes greatly differ according to their types of origin. To analyse this aspect, a quantitative method is applied, which can prop- erly characterise the dynamic nature of mor- phemes in terminology on the basis of a small sample. 1 Introduction In computational linguistics, the interest in ter- minological applications such as automatic term extraction is growing, and many studies use the quantitative information (cf. Kageura & Umino, 1996). However, the basic quantita- tive nature of terminological structure, which is essential for terminological theory and appli- cations, has not yet been exploited. The static quantitative descriptions are not sufficient, as there are terms which do not appear in the sam- ple. So it is crucial to establish some models, by which the terminological structure beyond the sample size can be properly described. In Japanese terminology, the roles of mor- phemes are different according to their types of origin, i.e. the morphemes borrowed mainly from Western languages (borrowed morphemes) and the native morphemes including Chinese- origined morphemes which are the majority. There are some quantitative studies (Ishii, 1987; Nomura g¢ Ishii, 1989), but they only treat the static nature of the sample. Located in the intersection of these two backgrounds, the aim of the present study is twofold, i.e. (1) to introduce a quantitative framework in which the dynamic nature of ter- minology can be described, and to examine its theoretical validity, and (2) to describe the quantitative dynamics of morphemes as a 'mass' in Japanese terminology, with reference to the types of origin. 2 Terminological Data 2.1 The Data We use a list of different terms as a sample, and observe the quantitative nature of the con- stituent elements or morphemes. The quantita- tive regularities is expected to be observed at this level, because a large portion of terms is complex (Nomura &: Ishii, 1989), whose forma- tion is systematic (Sager, 1990), and the quan- titative nature of morphemes in terminology is independent of the token frequency of terms, be- cause the term formation is a lexical formation. With the correspondences between text and terminology, sentences and terms, and words and morphemes, the present work can be re- garded as parallel to the quantitative study of words in texts (Baayen, 1991; Baayen, 1993; Mandelbrot, 1962; Simon, 1955; Yule, 1944; Zipf, 1935). Such terms as 'type', 'token', 'vo- cabulary', etc. will be used in this context. Two Japanese terminological data are used in this study: computer science (CS: Also, 1993) and psychology (PS: Japanese Ministry of Ed- ucation, 1986). The basic quantitative data are given in Table 1, where T, N, and V(N) in- dicate the number of terms, of running mor- phemes (tokens), and …

Content truncated to 500 words