: Dismax uses a strategy called Min-Should-Match which emulates the binary : operator in the Standard Handler. In a nutshell, this parameter (called mm) : specifies how many of the entered terms need to be present in your matched : documents. You can either specify an absolute number or a percentage. : : More information can be found here: : http://wiki.apache.org/solr/DisMaxQParserPlugin#mm_.28Minimum_.27Should.27_Match.29
in future versions of solr, dismax will use the q.op param to provide a default for mm, but in Solr 1.4 and prior, you should basically set mm=0 if you want the equivilent of q.op=OR, and mm=100% if you want the equivilent of q.op=AND -Hoss
