A System for Exploring NDLSH and LCSH Headings

Searching for foreign language books is difficult since it is more complicated to find appropriate foreign-language keywords than keywords in one’s native language. We present an approach that explores native- and foreign-language keywords and searches OPACs using them. We use the National Diet Library Subject Headings (NDLSH) and the Library of Congress Subject Headings (LCSH) as alternatives to keywords. The former are in Japanese, and the latter are in English. Users can explore connected headings, not only broader, narrower, and related terms but also other types of headings, including NDLSH and LCSH headings that are connected. The headings contained in searched books can also be connected. We developed a prototype system called Subject World on the Web that enables users to explore NDLSH and LCSH headings and to search in Osaka City University’s OPAC. Japanese-native users can explore NDLSH headings and find LCSH headings, and non-Japanese-native users can explore LCSH headings and find NDLSH headings to search and find both foreign and native books. We implemented our system using JavaScript and D3 so that it can be used by such general web browsers as Microsoft Edge, Chrome, and Safari. Our system is available to the public.