What is a “Discovery Layer”?
To me, a Discovery Layer allows a user to search across a library catalogue (or several), an ebook platform (or several), and a source of articles (or several).
- Federated Searching
- a query is distributed to multiple sources, and responses are compiled, de-duped, and returned
- e.g. Sirsi Single Search
- a single, regularly complied index is created from the collection of metadata from multiple sources
- e.g. Endeca, Google
- Single host environment
- users only have to learn one interface, instead of many
- users don’t have to choose from lists of dozens of indexes
- users don’t have to repeat searches depending on format (one search for books, then one for dissertations, then one for articles…)
- users expect simple, effective search tools like Google
The challenges that face the construction of a discovery layer include:
- many of our research tools are very difficult to extract data from as they make use of a multitude of non-standard formats and protocols
- most of our research tools (especially the library catalogue) generate search results with poor relevance ranking
- some sources will be rich in text and metadata (articles, ebooks) while other sources will only be represented by metadata (print books)
- The first uses tabs, like PubMed and Illumina
- The second uses facets, like Endeca, WorldCat, and VuFind
- The third uses page partitions, like Google Experimental and UBC’s OneSearch.
Coming up with what a user might deem relevant from 2 or 3 keywords is challenging in a regular search environment. Producing consistently relevant results in a federated or metasearch environment is extremely difficult.
- by taking into account the user’s previous searching behaviour
- by weighing results by the number of times an item has been bookmarked, printed, or saved
- by using citation information to determine ‘likeness’ (e.g. based on a percentage of shared citations in item’s bibliography)
- by using user-created lists articles to generate similar items of possible interest
- by knowing what courses a users is currently taking/teaching and emphasizing relevant resources accordingly
Is it realistic to expect a Discovery Layer to serve both the novice researcher and the expert to access a variety of formats in a multitude of disciplines? Can one size fit all? Should we develop several Discovery Layers with one for each discipline? (Arts, Social Sciences, Medicine). Should we develop one interface for undergraduates and one for faculty and graduate students?
Most discovery layers are still in the earliest stages of their development and by appearances, they seem more alike than unalike. How should we choose what is an acceptable product? One suggestion is to measure the success of a Discovery Layer by comparing its search results to Google.