Analysis on dynamics of research sub-domains in interdisciplinary fields: Analysis using personal distribution versus papers

Theoretically, we first classified interdisciplinary research to three types: 1) creating new field from inside of the scientific community, 2) collaboration among disciplines lead by the societal needs outside of the scientific community, 3) making suggestions for public. For analysis on dynamics of knowledge combination in interdisciplinary research, we developed an indicator using "relative transmission" concept and also sub-domain maps using quantification factor analysis (1974). We used a sub-domain matrix, which show the structure of submitting crossing over several sub-domains from one individual. Using "researcher" as a unit of the analysis, we analyzed dynamics of the blends / separation of sub-domain in interdisciplinary studies. Biophysics and environmental science, which are categorized as 1) and 2) in the above theoretical types, are chose for analysis. The total numbers of researchers are 516 and 346, in each field respectively, and observation year points are 1966, 1972, 1979, and 1984 for biophysics and 1977 and 1983 for environmental science. The results showed that the structure of groups of sub-domains in environmental science reflects the classical disciplines and there observed little combination in the knowledge, whereas in biophysics, the sub-domains are not fixed and there observed dynamics in knowledge integration. These tendency are considered to reflect the characteristics of the type- 2) and type- 1), respectively.