Library visibility on the Web

Introduction

Evergreen follows a number of best practices to make Library data integrate with the rest of the Web. Evergreen’s public catalog pages are designed so that search engines can easily extract meaningful information about your library and collections. Evergreen is also preparing for an eventual shift toward linked open bibliographic data.

Catalog data in search engines

Each record in the catalog is displayed to search engines using schema.org microdata.

Make sure your system administrator has not added a restrictive robots.txt file to your server. These files restrict search engines, up to the point of not allowing search engines to index your site at all.

Details of the schema.org mapping

  • Each item is listed as a schema:Offer, which is the same category that an online bookseller might use to describe an item for sale. These Offers are always listed with a price of $0.00.

  • Subject headings are exposed as schema:about properties.

  • Electronic resources are assigned a schema:url property, and any notes or link text are assigned a schema:description property.

  • Given a Library of Congress relator code for 1xx and 7xx fields, Evergreen surfaces the URL for that relator code along with the schema:contributor property to give machines a better chance of understanding how the person or organization actually contributed to this work.

  • Linking out to related records:

    • Given an LCCN (010 field), Evergreen links to the corresponding Library of Congress record using schema:sameAs.

    • Given an OCLC number (035 field, subfield a beginning with (OCoLC)), Evergreen links to the corresponding WorldCat record using schema:sameAs.

    • Given a URI (024 field, subfield 2 = 'uri'), Evergreen links to the corresponding OCLC Work Entity record using schema:exampleOfWork.

Viewing microdata

You can learn more about how Evergreen publicizes these data by viewing them directly. The structured data linter is a helpful tool for viewing microdata.

  1. Using your favorite Web browser, navigate to a record in your public catalog.

  2. Copy the URL that displays in your browser’s address bar.

  3. Go to http://linter.structured-data.org

  4. Under the Lint by URL tab, paste your URL into the text box.

  5. Click Submit

Other helpful features for search engines

  • Titles of catalog pages follow a "Page title - Library name" pattern to provide specific titles in search engine results pages, browser bookmarks, and browser tabs.

  • Links that robots should not crawl, such as search result links, are marked with the @rel="nofollow" property.

  • Catalog pages for record details and for library descriptions express a @rel="canonical" link to simplify the number of variations of page URLs that could otherwise have been derived from different search parameters.

  • Catalog pages that do not exist return a proper 404 "HTTP_NOT_FOUND" HTTP status code, and record detail pages for records that have been deleted now return a proper 410 "HTTP_GONE" HTTP status code.

  • Record detail and library pages include Open Graph Protocol markup.

  • Each library has its own page at http://localhost/eg/opac/library/LIBRARY_SHORTNAME that provides machine-readable hours and contact information.

SKOS support

Some vocabularies used (or which could be used) for stock record attributes and coded value maps in Evergreen are published on the web using SKOS. The record attributes system can now associate Linked Data URIs with specific attribute values. In particular, seed data supplying URIs for the RDA Content Type, Media Type, and Carrier Type has been added.

This is an experimental, "under-the-hood" feature that will be built upon in subsequent releases.

Previous
Next
To report a problem with this documentation or provide feedback, please contact the DIG mailing list.