bq: now if a user types "apples oranges" (without quotes) will the ranking be the same as when I had AND?
You haven't defined "same". But at root I think this is a red herring, you haven't stated why you care. They're different queries so I think the question is really which is more or less satisfactory when considering the use-case. Best, Erick On Wed, Jul 15, 2015 at 10:06 AM, Alessandro Benedetti <benedetti.ale...@gmail.com> wrote: > Talking about performances you should take a look to the difference in > performance between : > > > - disjunction of K sorted arrays ( n*k*log(k)) in Lucene - where *k* are > the disjunction clauses and *n* the average posting list size (just learned > today from an expert lucene committer)) > > - conjunction of K sorted arrays - not 100 % sure about the complexity, i > should check concretely the algorithm, but i suggest there is no > difference, or not so much difference ( I would be glad someone here to > show the resources, or knowledge) . > > basically when dealing with union or intersection of sorted arrays, the > algorithm that solve the two problems are quite comparable in term of > performances. > > I would say that the performance difference is irrelevant but i would like > someone to contradict me . > > Cheers > > > > 2015-07-15 17:34 GMT+01:00 Steven White <swhite4...@gmail.com>: > >> Hi Erick, >> >> I understand there are variables that will impact ranking. However, if I >> leave my edismax setting as is and simply switch from AND to OR as the >> default Boolean, now if a user types "apples oranges" (without quotes) will >> the ranking be the same as when I had AND? Will the performance be the >> same as when I had AND as the default? >> >> Thanks >> >> Steve >> >> On Wed, Jul 15, 2015 at 12:26 PM, Erick Erickson <erickerick...@gmail.com> >> wrote: >> >> > This is really an apples/oranges comparison. They're essentially >> different >> > queries, and scores aren't comparable across different queries. >> > >> > If you're asking "if doc 1 and doc 2 are returned by defaulting to AND or >> > OR, >> > are they in the same position relative to each other?" then I'm pretty >> > sure the >> > answer is "you can't count on it". You'll match on different fields >> > depending on >> > what the default is, and with boosting you just don't know. >> > >> > Best, >> > Erick >> > >> > On Wed, Jul 15, 2015 at 9:14 AM, Steven White <swhite4...@gmail.com> >> > wrote: >> > > By the way, using OR as the default, other than returning more results >> as >> > > more words are entered, the ranking and performance of the search >> remains >> > > the same right? >> > > >> > > Steve >> > > >> > > On Wed, Jul 15, 2015 at 12:12 PM, Steven White <swhite4...@gmail.com> >> > wrote: >> > > >> > >> Thank you all. Looks like OR is a better choice vs. AND. >> > >> >> > >> Charles: I don't understand what you mean by the "spellcheck >> component". >> > >> Do you mean OR works best with spell checker? >> > >> >> > >> Steve >> > >> >> > >> On Wed, Jul 15, 2015 at 11:07 AM, Reitzel, Charles < >> > >> charles.reit...@tiaa-cref.org> wrote: >> > >> >> > >>> A common approach to this problem is to include the spellcheck >> > component >> > >>> and, if there are corrections, include a "Did you mean ..." link in >> the >> > >>> results page. >> > >>> >> > >>> -----Original Message----- >> > >>> From: Walter Underwood [mailto:wun...@wunderwood.org] >> > >>> Sent: Wednesday, July 15, 2015 10:36 AM >> > >>> To: solr-user@lucene.apache.org >> > >>> Subject: Re: Which default Boolean operator to set, AND or OR? >> > >>> >> > >>> The AND default has one big problem. If the user misspells a single >> > word, >> > >>> they get no results. About 10% of queries are misspelled, so that >> > means a >> > >>> lot more failures. >> > >>> >> > >>> wunder >> > >>> Walter Underwood >> > >>> wun...@wunderwood.org >> > >>> http://observer.wunderwood.org/ (my blog) >> > >>> >> > >>> >> > >>> On Jul 15, 2015, at 7:21 AM, Jack Krupansky < >> jack.krupan...@gmail.com> >> > >>> wrote: >> > >>> >> > >>> > It is simply precision (AND) vs. recall (OR) - the former tries to >> > >>> > limit the total result count, while the latter tries to focus on >> > >>> > relevancy of the top results even if the total result count is >> > higher. >> > >>> > >> > >>> > Recall is good for discovery and browsing, where you sort of know >> > what >> > >>> > you generally want, but not exactly with any great precision. >> > >>> > >> > >>> > Recall will include results that almost meet the query terms, but >> > >>> > maybe some are missing. >> > >>> > >> > >>> > Precision will guarantee and insist that all query terms are >> present. >> > >>> > >> > >>> > One great example for recall is a plagiarism query - enter all the >> > >>> > terms for a passage and then find documents that most closely >> > >>> > approximate the passage without being necessarily exact matches. >> IOW, >> > >>> > the plagiarizer changes a word here and there. >> > >>> > >> > >>> > -- Jack Krupansky >> > >>> > >> > >>> > On Wed, Jul 15, 2015 at 8:16 AM, Steven White < >> swhite4...@gmail.com> >> > >>> wrote: >> > >>> > >> > >>> >> Hi Everyone, >> > >>> >> >> > >>> >> Out-of-the box, Solr (Lucene?) is set to use OR as the default >> > >>> >> Boolean operator. Can someone tell me the advantages / >> > disadvantages >> > >>> >> of using OR or AND as the default? >> > >>> >> >> > >>> >> I'm leaning toward AND as the default because the more words a >> user >> > >>> >> types, the narrower the result set should be. >> > >>> >> >> > >>> >> Thanks >> > >>> >> >> > >>> >> Steve >> > >>> >> >> > >>> >> > >>> >> > >>> >> > ************************************************************************* >> > >>> This e-mail may contain confidential or privileged information. >> > >>> If you are not the intended recipient, please notify the sender >> > >>> immediately and then delete it. >> > >>> >> > >>> TIAA-CREF >> > >>> >> > ************************************************************************* >> > >>> >> > >>> >> > >> >> > >> > > > > -- > -------------------------- > > Benedetti Alessandro > Visiting card - http://about.me/alessandro_benedetti > Blog - http://alexbenedetti.blogspot.co.uk > > "Tyger, tyger burning bright > In the forests of the night, > What immortal hand or eye > Could frame thy fearful symmetry?" > > William Blake - Songs of Experience -1794 England
