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>not the right approach. And yet...I wish I could explain why it seems as >though the clustering can tell us something. Well, what is it you think the clustering can tell you something _about_? This is an interesting topic to me. I'm not sure the clustering can tell you anything about relevance to the user. I'm not seeing it. I mean, the number of items that are members of a FRBR work set really just indicates how many 'versions' (to be imprecise) of that work exist. But the number of 'versions' of a work that exist doesn't really predict how likely that work (or any of it's versions) is to be of interest to a user, does it? But maybe you're thinking of something I'm missing, I'm curious what you're thinking about. I am a big fan of grouping items into FRBR work sets however, for other reasons (which may or may not be obvious). But exactly how this should be done, under what control of the user, is still an open question to some extent (that will only be answered after more systems try and it experiment with it). I wonder---if more than one item in the FRBR work set has an especially high relevancy ranking (I don't know what would qualify as 'especially high')---if more than one of those items should in fact be "brought to the top", and hilighted on the first-level display? Instead of making the user "click through" to see them? But I'm assuming you hide members of a FRBR work grouping behind a single heading on the first level results---you may not do this, you may just group them adjacently but put all of them on the first level result list? There are a million ways to do these things. And, as Thom mentions, it's also something of an open question as to what the right way to do relevancy rankings based on bib records is anyway (or if there even is a right way). So many questions. But that's what makes it interesting. I am very interested in checking out the system you end up with, Colleen, it sounds interesting. If it's publically internet accessible, please do share it with us when there's something interesting to look at. --Jonathan >--Colleen > >David Walker wrote: > >>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:[log in to unmask]] On Behalf Of >>Hickey,Thom >>Sent: Monday, April 10, 2006 12:52 PM >>To: [log in to unmask] >>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:[log in to unmask]] On Behalf Of >>Jonathan Rochkind >>Sent: Monday, April 10, 2006 3:16 PM >>To: [log in to unmask] >>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:[log in to unmask]] On Behalf Of >>>Colleen Whitney >>>Sent: Monday, April 10, 2006 2:04 PM >>>To: [log in to unmask] >>>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:[log in to unmask]] On Behalf >>>> >>Of >> >>>>Colleen Whitney >>>>Sent: Monday, April 10, 2006 1:06 PM >>>>To: [log in to unmask] >>>>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