262-432-5200 call came in today just before 2pm EST- no message but phone showed call came from someone listed as "The DRG" so I did an inquiry that produced this result. The Dieringer Research Group, Inc. 200 Bishops Way. Brookfield, WI 53005. 262-432-5200. 888-432-5220. Caller: The Dieringer Research Group, Inc. Call type: Survey.