In my web application log files I see part of the Fredhopper query being logged:
2015-06-17 16:56:47,073 DEBUG Query - FutureTask - 103 - Constructing Fredhopper query
2015-06-17 16:56:47,158 INFO Query - FutureTask - 103 - Executing query: fh_location=//catalog01/en_US/categories<{catalog01_tcm_0_19_1}&fh_user_date=20150617&st_region=Banner+List&st_active_period=20150617&st_publication=tcm%3A0-19-1&sc_auth_isauthenticated=false&sc_session_lifetime=0&sc_ua_isbot=false
It seems that the easiest way to debug and test the results of tweaking the queries is to directly query the Fredhopper Query Server by URL and see how the result set changes. I am not sure how to take this information from the log and build a full URL to query. Does anyone know the full Query URL syntax?