Problem 1 consisted of artificial data simulated from an oligogenic (four-locus) disease model. The data set contained 200 nuclear families with at least one affected child and 100 control families with no affected members. Two of the disease loci were intended to be detectable via association analysis but not necessarily via linkage analysis, and the other two were virtually undetectable in this data set. Participants used association analysis, linkage analysis, and segregation analysis to analyze these data. Their findings are summarized, and analysis strategies are discussed. ©1995 Wiley-Liss, Inc.