category facet derived from library call numbers

[solrize]

kcoyle forwards email from Jonathan Rothman of U. Michigan. If I understand the email, it is that Umich and other libraries including LC and Dewey have a way to map call numbers to subject categories, so we should derive these categories and insert them into the search index and display search result categories in a facet. I think we have also had some other discussion about this, maybe relating to ONIX.

[solrize (solrize)]

One obvious question: what about the subject fields that are already in our catalogue records? Were they derived this way? Will there likely be useful info in the call numbers that's not already in the subject fields? I guess this question is primarily about LC records.

[George (george-archive)]

We could show library metadata on Subject pages. Like, if you're looking at openlibrary.org/subjects/cheese, you'd see a little metadata list with the various call numbers etc.