Constructing a true LCSH tree of a science and engineering collection

Abstract

The Library of Congress Subject Headings (LCSH) is a subject structure used to index large library collections throughout the world. Browsing a collection through LCSH is difficult using current online tools in part because users cannot explore the structure using their existing experience navigating file hierarchies on their hard drives. This is due to inconsistencies in the LCSH structure, which does not adhere to the specific rules defining tree structures. This article proposes a method to adapt the LCSH structure to reflect a real‐world collection from the domain of science and engineering. This structure is transformed into a valid tree structure using an automatic process. The analysis of the resulting LCSH tree shows a large and complex structure. The analysis of the distribution of information within the LCSH tree reveals a power law distribution where the vast majority of subjects contain few information items and a few subjects contain the vast majority of the collection.

Reducing subject tree browsing complexity

“…This fact, pointed out by Bates (), has been confirmed empirically for subject hierarchies such as the Yahoo! web directory (Liu et al., ), DDC (Wang & Lee, ), and LCSH (Julien et al., ). Power law distributions are common in organized information found in other knowledge domains (Egghe, ; Newman, ), so there are strong indications that organized collections in general follow the same kind of distribution within their organizing structure.…”

How are Cookbooks Classified in Libraries? An Examination of LCSH and LCC

“…This is the first research project that looks at cooking subject headings and classification numbers in LCSH and LCC. There have been several studies about how LCSH and LCC treat a variety of subjects, and current studies include Christensen (2008), Drabinski (2013), and Julien et al (2012).…”

Library of congress subject heading (LCSH) browsing and natural language searching

“…LCSH authority records contain broader/narrower term relationships but it was not conceived as a hierarchical thesaurus; this is addressed computationally based on Julien et al (2012) who have retrofitted LCSH into a topical hierarchy. The process extracts the LCSHs assigned to the bibliographic collection, which are matched to an authority record to place each bibliographic record in the LCSH hierarchy.…”

“…Some researchers have developed algorithms to modify large topic structures that can overwhelm users; our LCSH hierarchy was simplified using the automated process described in Julien et al (2013). The approach opportunistically prunes a topic tree based on the expected power law distribution of topic assignments to the collection, which are common in organized information (Julien et al, 2012). Capitalizing on this trend, Julien et al (2013) reduce the size and depth of a collection's subject tree by pruning the subjects that are not representative of a collection, which was applied to our LCSH hierarchy.…”

“…Our dataset is comprised of 1) a collection of 122,197 bibliographic records housed at McGill University's Schulich Library of Science and Engineering, and 2) its roughly 205,000 LCSH authority records. The domain of science was selected as an extreme test for this study since it offers the deepest and most connected portion of the LCSH structure (Julien, Tirilly, Leide, & Guastavino, 2012;Yi & Chan, 2010).…”