Search is defaulting to an OR combination of the search terms, which IMHO is a mistake (and also, BTW not the default on Google). I would prefer search to default to ANDing the terms instead of ORing or at least have the possibility to configure this as a preference.
This has been annoying me for some time now, and I'm hoping this could be reconsidered.
It is unintuitive. Most search engines, most notably Google, have trained people to narrow their search by adding more keywords, but with OR search doing this actually broadens the search, making it less specific. Since it's not even obvious that this is happening, I suspect a lot of people probably just give up on using the built-in search, possibly leading to more duplication.
It is inconsistent with the other search operators, including tags, which require that all of them must match (i.e. AND).
OR search only works with the "relevancy" ordering. I often find myself looking for a question I knew was popular, but when I try ordering by votes, I inevitably end up having one of my keywords match one of the top questions, and adding more keywords only makes it worse. Similarly, sorting by "active" is also not very useful.
While it is possible to work around this by prefixing every search keyword with
+, I think this is a hassle and easy to forget. The system should be optimized for the common case, which in my experience is AND-search.
+1. Search functionality of any sort is only useful when there are enough items that it's not feasible to look through all of them to find what you want. Therefore it's obvious that setting a single search term will limit the list of items that you have to browse through to find what you want. And by inductive reasoning users will expect that since adding 1 term reduced the list of items, adding another term will further reduce it. Q.E.D.
-0.8. In the actual search string the semantics of
+ are obvious, and their precedence is also obviously equal. But if search is
and-centric, is there any ASCII character which can signify boolean
or and establish the precedence of it relative to
-? That is (using
| as the
or symbol for illustration), can a normal user be expected to divine the meaning of
-0.3. If searches are ranked by the number of matched keywords (weighted for rarity, of course) then the
or-centric first results are similar (and possibly equal) to the
and-centric result, and it allows for a bit of typos and adding of words which are in fact not in the post.
But too late to change my vote.
ANDing instead of ORing is a bad idea, lets use an example - someone is searching for
how to create a master page in C# asp.net
By default these terms are ORd together, and the results ranked and sorted by the frequency that each term appears in the document (for example the term "C#" is far more common than the term "Page" or "Master" and so when scoring pages more emphasis is given to these terms). The end result is many pages, however because of the ranking the ones that contain most or all of the given terms end up at the top of the results.
However crucially note that although results that contain all terms are favoured, results don't have to contain all the terms - for example there may be many useful questions on master pages that don't use the words "how" or "to" (which are not considered stop words).