Measuring Closure Properties of Patent Sublanguages

Patent search is an important information retrieval problem in scientific and busi-ness research. Semantic search would be a large improvement to current technolo-gies, but requires some insight into the lan-guage of patents. In this article we test the fit of the language of patents to the sublan-guage model, focussing on closure prop-erties. The research presented here is rel-evant to the topic of sublanguage identi-fication for different domains, and to the study of the language of patents. We in-vestigate the hypothesis that fit to the sub-language model increases as one moves down the International Patent Classifica-tion hierarchy. The analysis employs a general English corpus and patent docu-ments from the MAREC corpus. It is shown that patents generally fit the sub-language model, with some variability be-tween categories in the extent of the fit.