I presume by full text search you mean the Lucene search engine, which uses the Vector Space Model? If you know a bit about Lucene, you wouldn't be surprised by what they've done. If you log the output of lsearchd, you can see how it blows up queries: original query: prefrontal cortex hippocampus query=[prefrontal cortex hippocampus] parsed=[(+(contents:prefrontal contents:prefront^0.5) +contents:cortex +contents:hippocampus) ((+title:prefrontal^6.0 +title: cortex^6.0 +title:hippocampus^6.0) (+(stemtitle:prefrontal^2.0 stemtitle:prefront^0.8) +stemtitle:cortex^2.0 +stemtitle:hippocampus^2.0)) ((+alttitle1:prefrontal^4.0 +alttitle1:cortex^4.0 +alttitle1:hippocampus^4.0) (+alttitle2:prefrontal^4.0 +alttitle2:cortex^4.0 +alttitle2:hippocampus^4.0) (+alttitle3:prefrontal^4.0 +alttitle3:cortex^4.0 +alttitle3:hippocampus ^4.0))] If you compare that to what pubmed does for the same query: ("prefrontal cortex"[MeSH Terms] OR ("prefrontal"[All Fields] AND "cortex"[All Fields]) OR "prefrontal cortex"[All Fields]) AND ("hippocampus"[MeSH Terms] OR "hippocampus"[All Fields]) On Thu, Jan 8, 2009 at 11:22 AM, Brion Vibber <brion(a)wikimedia.org> wrote: -- You have successfully failed!