Locke indicated that the subject categories are not perfect, partly because of the ISI structure. In the area of computer science, there are about 6 subdivisions, e.g. artificial intelligence. He looked at grouping them that way rather than by author affiliation because of the inconsistency of the way data is input. We would miss out on those that don't have departmental affiliation. In subject areas we get faculty in departments that are not named specifically that way.
Biotechnology can come from all sorts of departments.
He had to pull out some individual journal titles that don't fall into those targeted categories, e.g. Biotechniques. Using those cited by gives you conference proceedings, technical reports and monographs-that shows what faculty are really using. He used the ranked or cited work vs. cited reference. ISI is inconsistent in the way they list a work. He used JCR plus the journal title abbreviations.