FUNCIONAMIENTO DEL TANQUE

Since 2006, a small number of academic libraries have implemented faceted navigation on their online catalogs. Among them are McMaster University Library (Hamilton, Ontario, Canada), State University Libraries of Florida, NC State University Library (Raleigh, North Carolina), and WorldCat. In recent years, faceted navigation has grown to be a well-accepted approach and has been applied as a standard technique on commercial websites for many years (Breeding, 2007). Since the adoption of faceted search by the NC State University Library in early 2006, faceted library catalogs have gained popularity in many academic and public libraries. Many library automation vendors and software companies have produced applications for facets (e.g., Endeca, AquaBrowser, Encore, Primo, Smart Library System, OPAC GiB, etc.), and some programmers and librarians have worked together to develop open source faceted integrated library systems (ILS) (Evergreen, Koha, Solr, VuFind, etc.).

Endeca, a well-known company for providing facet search applications to e- commerce sites, started the implementation of facet browsing in their catalog. Figure 2.7

presents the interface of NC State’s library catalog, which acquired the Endeca applications in 2005. This new generation of library catalog gives its users both relevance-ranked keyword search results and rich facet metadata previously trapped in MARC records to enhance collection browsing and search refinement. The faceted metadata are grouped into subject, genre, format, location, author, etc. A user may enter the text query in the query box as a starting point and then click one attribute of facets from the left-hand box to filter the result set. An empty query in the query box will generate the results for the whole collection held by the library, organized by a set of facets. In addition to simple text search mode combined with facet browsing, users also can select other search modes, for example to browse through new titles that have been recently cataloged by the system, and to scan through the LCSH.

AquaBrowser is another world leader application in visual faceted search that connects to heterogeneous data sources. AquaBrowser can be found in public, academic and special libraries around the United States and the world. AquaBrowser motivates users to explore the library’s content by incorporating various common search behaviors. Its unique ‘search, discover, refine’ methodology provides features that help users quickly and easily uncover relevant results. Figure 2.8 captures a screenshot from Queens Library, which implements AquaBrowser as its search solution. This OPAC’s facet implementation is similar to that of the NC State University catalog, except that the facet panel is placed on the right side. Another major difference is the word cloud on the left side that explores associations between the current query and other vocabularies as a query recommendation tool. Another development is the separation of collections according to item type, i.e., books, music, movies, etc.

Figure 2.7 Interface of North Carolina State University’s faceted library catalog

Encore is another popular commercial application for faceted library catalogs. In addition to faceted navigation and relevance ranking, it also presents tag clouds, popular choices, and recently added suggestions. Encore even makes use of user contributions as a tool for discovery by incorporating community participation features, such as tagging.

Primo is an Ex Libris offering that aims to revitalize the library environment by creating next-generation interfaces. According to Ex Libris, Primo provides services for searching as well as delivering access to all of the library’s resources, whether those resources are maintained and hosted locally or need to be accessed remotely. In addition to relevance ranking and faceted browsing, Primo indexes data from sources such as Syndetic Solutions, Blackwell, Amazon and others to provide additional access points when searching. It also includes features that are popular in e-commerce websites, such as user- supplied reviews, recommendations based on what others who viewed the same item selected, and grouping similar results. Primo also includes dictionaries and thesauri to provide search suggestions and structured lists as part of the search process.

In addition to commercial search solutions for faceted OPACs, some open source catalogs have been developed by programmers and librarians. These catalogs aim to be next- generation catalogs and regard facet searching as one of their major features. Also, open source OPACs are more cost-effective than proprietary ones, so many libraries choose to use open source solutions mainly for their affordability. Although users of open source OPACs may experience difficulties with installation and incomplete documentation, they are modestly more satisfied than users of proprietary OPACs (Riewe, 2008). Some common open source OPACs are Evergreen, Koha, Solr, VuFind, etc.

Evergreen is an open source ILS developed in 2004 by a consortium of public libraries in Georgia. Currently, as the largest open source ILS, scalability has not been an issue for Evergreen, which accommodates 1.8 million patrons and a collection of 9 million items (Riewe, 2008). Since 2007, the Michigan Libraries Consortium has installed Evergreen. British Columbia, which installed Evergreen in three libraries, estimated a huge cost reduction compared to proprietary ILS. Figure 2.9 presents an Evergreen interface from the Georgia Public Libraries. The most important feature of this faceted navigation is that it uses facets created from results to submit new searches instead of refining existing searches. Thus, each facet serves as a query recommendation. In addition, the facet hierarchy allows for third-level facet values, which is different from most faceted navigations that allow only a two-level hierarchy.

Figure 2.9 Interface of Georgia Public Libraries faceted library catalog

This section provides a comprehensive, but not necessarily exhaustive, overview of some well-known faceted search projects, either for general purposes, personal information

management, or library catalogs. Despite the differences among the implementations, most faceted search systems offer users two-level faceted metadata for refining the text search or browsing the whole collection. Most systems allow a single choice of facet value under the same facet and multiple choices of facets. Overall, the facet feature has provided more powerful search assistance for users than was available prior to the introduction of facet searches.