Actually we've been experimenting with 'audience level' (http://www.oclc.org/research/projects/audience/) which attempts to address that, based on what type of libraries hold the items. It should help, but again, this is new and we don't have much more than anecdotal evidence so far, and how to work it into a user interface may be a challenge. The latest thinking is that it may make sense to have three categories: juvenile, general, and specialized.
--Th -----Original Message----- From: Code for Libraries [mailto:[EMAIL PROTECTED] On Behalf Of David Walker Sent: Monday, April 10, 2006 4:06 PM To: CODE4LIB@LISTSERV.ND.EDU Subject: Re: [CODE4LIB] Question re: ranking and FRBR The only tricky thing about this with WorldCat, though, is that you have such a large mix of libraries. In my own searching on WorldCat, I've noticed that a fair amount of fiction and non-scholarly works appear near the top of results because the public libraries are skewing the holdings of those titles. Not a bad thing in itself, if that's what I'm looking for, but our students are looking for scholarly works (and still learning to distinguish scholarly from not), so would be nice in our particular context to limit only to academic libraries that own the title. --Dave ========================= David Walker Web Development Librarian Library, Cal State San Marcos 760-750-4379 http://public.csusm.edu/dwalker ========================= -----Original Message----- From: Code for Libraries [mailto:[EMAIL PROTECTED] On Behalf Of Hickey,Thom Sent: Monday, April 10, 2006 12:52 PM To: CODE4LIB@listserv.nd.edu Subject: Re: [CODE4LIB] Question re: ranking and FRBR I'd agree with this. Actually, though, 'relevancy' ranking based on where terms occur in the record and how many times they occur is of minor help compared to some sort of popularity score. WorldCat holdings work fairly well for that, as should circulation data. The primary example of this sort of ranking is the web search engines where ranking is based primarily on word proximity and links. --Th -----Original Message----- From: Code for Libraries [mailto:[EMAIL PROTECTED] On Behalf Of Jonathan Rochkind Sent: Monday, April 10, 2006 3:16 PM To: CODE4LIB@LISTSERV.ND.EDU Subject: Re: [CODE4LIB] Question re: ranking and FRBR When you are ranking on number of holdings like OCLC is, a straight sum makes sense to me---the sum of all libraries holding copies of any manifestation of the FRBR work is indeed the sum of the holdings for all the records in the FRBR work set. Of course. If you're doing relavancy rankings instead though, a straight sum makes less sense. A relevancy ranking isn't really amenable to being summed. The sum of the relevancy rankings for various manifestations/expressions is not probably not a valid indicator of how relevant the work is to the user, right? And if you did it this way, it would tend to make the most _voluminous_ work always come out first as the most 'relevant', which isn't quite right.---This isn't quite the same problem as OCLC's having the bible come out on top---since OCLC is ranking by holdings, it's exactly right to have the bible come out on top, the Bible is indeed surely one of the (#1?) most held works, so it's quite right for it to be on top. But the bible isn't always going to be the most relevant result for a user, just because it's the most voluminous! Summing is going to mess up your relevancy rankings. Just using the maximum relevancy ranking from the work set seems acceptable to me--the work's relevancy to the user is indicated by the most relevant manifestation in the set. There might be a better way to do it (Is a work with four manifestations with a relevancy ranking .7 more relevant than a work with just one manifestation with a ranking of .9? I don't think it probably is, actually; I think just taking the maximum should work fine. But it depends on the relevancy algorithm maybe.). I don't think I'm enough of a mathematician to understand the point of the log of the sum, though, hmm. --Jonathan At 2:38 PM -0400 4/10/06, Hickey,Thom wrote: >We're doing straight sums of the holdings of all the manifestations in >the work. It's hard for me to see the need to discount holdings in >multiple manifestations. It does mean that 'bible' tends to come to the >top for many searches, but that's about the only work-set I see coming >up unexpectedly to the top. > >If we had circulation data we'd certainly factor that in (or maybe just >use it if it was comprehensive enough). > >--Th > > >-----Original Message----- >From: Code for Libraries [mailto:[EMAIL PROTECTED] On Behalf Of >Colleen Whitney >Sent: Monday, April 10, 2006 2:04 PM >To: CODE4LIB@LISTSERV.ND.EDU >Subject: Re: [CODE4LIB] Question re: ranking and FRBR > >Thanks...is it just a straight sum, Thom? > >--C > >Hickey,Thom wrote: > >>Here at OCLC we're ranking based on the holdings of all the records in >>the retrieved work set. Seems to work pretty well. >> >>--Th >> >>-----Original Message----- >>From: Code for Libraries [mailto:[EMAIL PROTECTED] On Behalf Of >>Colleen Whitney >>Sent: Monday, April 10, 2006 1:06 PM >>To: CODE4LIB@LISTSERV.ND.EDU >>Subject: [CODE4LIB] Question re: ranking and FRBR >> >>Hello all, >> >>Here's a question for anyone who has been thinking about or working >with >>FRBR for creating record groupings for display. (Perhaps others have >>already discussed or addressed this...in which case I'd be happy to >have >>a pointer to resources that are already out there.) >> >>In a retrieval environment that presents ranked results (ranked by >>record content, optionally boosted by circulation and/or holdings), how >>could/should FRBR-like record groupings be factored into ranking? >>Several approaches have been discussed here: >> - Rank the results using the score from the highest-scoring record in >a >>group >> - Use the sum of scores of documents in a group (this seems to me to >>place too much weight on the group) >> - Use the log of the sum of the scores of documents in a group >> >>I'd be very interested in knowing whether others have already been >>thinking about this.... >> >>Regards, >> >>--Colleen Whitney >> >>
