Boosting on recency is probably a better approach. A fixed re-ranking horizon will always be a compromise, a guess at the precision of the query. It will give poor results for queries that are more or less specific than the assumption.
Think of the recency boost as a tie-breaker. When documents are similar in relevance, show the most recent. This can work over a wide range of queries. For “malaysian airlines crash”, there are two sets of relevant documents, one set on MH 370 starting six months ago, and one set on MH 17, two months ago. But four hours ago, The Guardian published a “six months on” article on MH 370. A recency boost will handle that complexity. wunder Walter Underwood wun...@wunderwood.org http://observer.wunderwood.org/ On Sep 5, 2014, at 10:23 AM, Erick Erickson <erickerick...@gmail.com> wrote: > OK, why can't you switch the clauses from Joel's suggestion? > > Something like: > q=Malaysia plane crash&rq={!rerank reRankDocs=1000 > reRankQuery=$myquery}&myquery=*:*&sort=date+desc > > (haven't tried this yet, but you get the idea....). > > Best, > Erick > > On Fri, Sep 5, 2014 at 9:33 AM, Markus Jelsma > <markus.jel...@openindex.io> wrote: >> Hi - You can already achieve this by boosting on the document's recency. The >> result set won't be exactly ordered by date but you will get the most >> relevant and recent documents on top. >> >> Markus >> >> -----Original message----- >>> From:Ravi Solr <ravis...@gmail.com <mailto:ravis...@gmail.com> > >>> Sent: Friday 5th September 2014 18:06 >>> To: solr-user@lucene.apache.org <mailto:solr-user@lucene.apache.org> >>> Subject: Re: Query ReRanking question >>> >>> Thank you very much for responding. I want to do exactly the opposite of >>> what you said. I want to sort the relevant docs in reverse chronology. If >>> you sort by date before hand then the relevancy is lost. So I want to get >>> Top N relevant results and then rerank those Top N to achieve relevant >>> reverse chronological results. >>> >>> If you ask Why would I want to do that ?? >>> >>> Lets take a example about Malaysian airline crash. several articles might >>> have been published over a period of time. When I search for - malaysia >>> airline crash blackbox - I would want to see "relevant" results but would >>> also like to see the the recent developments on the top i.e. effectively a >>> reverse chronological order within the relevant results, like telling a >>> story over a period of time >>> >>> Hope i am clear. Thanks for your help. >>> >>> Thanks >>> >>> Ravi Kiran Bhaskar >>> >>> >>> On Thu, Sep 4, 2014 at 5:08 PM, Joel Bernstein <joels...@gmail.com >>> <mailto:joels...@gmail.com> > wrote: >>> >>>> If you want the main query to be sorted by date then the top N docs >>>> reranked by a query, that should work. Try something like this: >>>> >>>> q=foo&sort=date+desc&rq={!rerank reRandDocs=1000 >>>> reRankQuery=$myquery}&myquery=blah >>>> >>>> >>>> Joel Bernstein >>>> Search Engineer at Heliosearch >>>> >>>> >>>> On Thu, Sep 4, 2014 at 4:25 PM, Ravi Solr <ravis...@gmail.com >>>> <mailto:ravis...@gmail.com> > wrote: >>>> >>>>> Can the ReRanking API be used to sort within docs retrieved by a date >>>> field >>>>> ? Can somebody help me understand how to write such a query ? >>>>> >>>>> Thanks >>>>> >>>>> Ravi Kiran Bhaskar >>>>> >>>> >>> >>
