http://tags.library.upenn.edu/tag/to_read+facets PennTags Feed http://tags.library.upenn.edu/makerecord/url/23871 http://tags.library.upenn.edu/makerecord/url/23871 "Facet-based interfaces demonstrate some limitations of Library of Congress Subject Headings (LCSH), which were designed to deal with constraints that do not exist in the current computerized environment. This paper discusses some challenges for using LCSH for faceted browsing and navigation in library catalogs. Ideas are provided for improving results through system design, changes to LCSH practice, and LCSH structure."