Friday, April 25, 2008

Better maps! More bibliographic detail!

New BHL Map interface

Following some excellent suggestions gathered at a recent Encyclopedia of Life meeting, we've made changes to our Google Maps browse interface. To recap, we take Library of Congress Subject Headings and geocode and map them using the Google Maps API (details here).

Now that we're managing nearly 10,000 volumes the standard Google Maps interface was getting cluttered and clunky, so we've refined the interface to show smaller points, weight the results using color, and display links to the titles for a given subject heading within the map itself (as demonstrated for "Africa" above). To view the map in full, visit

We made another change based on requests to view full bibliographic details for a scanned title. When we harvest scans from the Internet Archive, we copy the MARCXML for the title to our servers and siphon off just enough of the metadata to facilitate our browse & search capabilities - to pull in the contents of the entire MARCXML would unnecessarily bloat our database with info we don't expect to search across or expose via browse. But, it's important data to have in the display, so we've skinned the MARCXML using XSLTs provided by the Library of Congress. To view in action, click the "Brief|Detailed|MARC" links at, or for any title in our collection.

Finally, we've enhanced the display for our Discovered Bibliographies to return results in a more performant way, providing more visual feedback to the user that processes are at work. To view the refined interface, visit the result for Pomatomus saltatrix at

Tuesday, April 15, 2008

BHL Portal Updates!

The BHL portal ( has been updated with the following changes:

  • A new option has been added to filter results by the language in which items are published. For example, Titles published in English, or Authors with works published in German. This option complements the pre-existing option to filter results by contributing institution.
  • An advanced search page ( has been added. This page allows a user to search on any combination of search categories (Titles, Authors, Names, or Subjects), instead of just one or all of the categories. It also allows search results to be limited by the publishing language.
  • OCLC numbers associated with each title have been cleaned up. This means that the “Find in a local library” link on each title’s bibliography page should now work correctly.
  • Sorting of individual items within a single title has been improved. See the right side of this page ( for an example. You can see that the volumes are listed in order, v1 to v 92. Prior to the correction, the volumes were sorting as follows: v1, v10, v11, v12, … v2, v20, v21, v22, … v3, v30, v31, v32.
  • Call numbers, when available, should now display correctly on bibliography pages.
  • Some minor updates have been made to the page that displays the discovered bibliography for a name. An example is Changes have been made to retrieve data as needed, instead of all at once, which has improved performance greatly. However, there remains a lengthy delay in retrieving large data sets, so we know that more work is needed here. At a minimum, we know that we need to improve the feedback given to the user while large data sets are being retrieved.

Also of note:

Some inconsistencies with title information have been identified. We had believed that the MARC leader assigned to an item would be sufficient to uniquely identify a title. This has turned out to not be the case (affecting about one-half of one percent of the titles we’ve ingested from Internet Archive), so we’ve had to adjust how we identify which items belong to which titles. The cleanup of this data is ongoing.

- Mike Lichtenberg