Which default Boolean operator to set, AND or OR?

[Steven White]

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