LCSH is to Thesaurus as Doorbell is to Mammal: Visualizing Structural Problems in the Library of Congress Subject Headings

Simon E Spero


The Library of Congress Subject Headings (LCSH) has been
developed over the course of more than a century. Before 1986, only “See Also”
references were available. In that year, an attempt was made to automatically
convert these references into standardized hierarchical and associative thesaural
relations. This process was highly unreliable. Unfortunately 20 years later most
records still have not had their references evaluated, making their use in automated
processes problematic. As part of our work on converting the Headings into SKOS,
this project has experimented with different graph visualizations of the tangled web
of broader terms embedded in LCSH. This poster will demonstrate several of these
renderings, show how they can help users to judge which relationships might not be
correct, and reveal the true relationship between Doorbells and Mammals. A sample
visualization is available online at

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