What is a Discovery Layer?


Last updated October 4, 2012.

Discovery Layers are a relatively new software component for libraries that provide a search interface for users to find information held in the library’s catalog and beyond. Typically, a Discovery Layer is based on an enterprise search platform that can interact with a metadata index and will normally include additional features that allow your library to customize the search results.

FOSS Discovery Layer software now provides a strong alternative to early commercial products such as Aquabrowser, Primo or Encore. Open Source search components, such as Apache Solr, are used widely even among commercial products; however, different configurations will generally have varying degrees of proprietary elements.

As a new concept, Discovery Layer systems are still evolving and there is no hard and fast definition of what constitutes an idealized system. They first developed as a direct result of the ‘decoupling’ of catalog search and browse functionality from the integrated library management system (ILS). The primary function of a Discovery Layer is a user interface that allows patrons to navigate and find information. This generally sits atop harvested metadata such as catalog records, index/abstract records, and other information from local and/ or remote databases.

The Discovery Layer interface will generally provide a unified view across resources such as local archival management systems, institutional repositories or the catalog component of a library management system. Some will even crawl local websites. Harvested data is indexed and presented to the end user in a single set of results.

Most systems lie somewhere between a traditional ILS catalog search and web search engine. In general, a Discovery Layer provides a more structured view of results than a web search engine. Refined versions of search and discovery options are available on e-commerce sites such as Amazon or eBay. There will be an expectation that data underpinning the service is richer and tailored for academic or local user group needs.

Discovery layer products are usually deployed alongside or as an outright replacement to a traditional online public access catalog (OPAC). They can be seen as a response of sorts to the allegation that traditional online catalog interfaces do not reflect the modern day search engine experience that a web native generation of users expect.

One key factor for a Discovery Layer is that it indexes data that lies outside the library’s immediate catalog - e.g. web based content stored remotely, metadata for copyrighted works not in the library catalog, or content stored in other libraries. The Discovery Layer can therefore cover a far greater scope than a simple search of the library catalog.