The comparison of the rape estimates between the two surveys shows that the effects of not using comparable definitions of rape produced erroneous comparisons of data on the extent of rape and decisions about the statistical significance of differences between the two survey estimates. Valid rape comparisons between the surveys were only made possible by modifying the reference period to include only incidents that happened since the age of 16 and excluding digital and object penetration of the victim. An unanticipated measurement issue arose in attempting to determine whether to put boyfriend or date rape perpetrators into either the intimate partner or acquaintance category when compiling estimates for different victim-perpetrator relationships. Researchers who design cross-national comparisons of the prevalence and features of rape should focus on equating survey designs as much as possible, so that comparisons can be valid and easily obtained. Otherwise, comparisons must take into account differences in estimates due to factors in definitions and survey design and modify estimates accordingly. This study focused on the following factors as critical in comparisons of cross-national rape data: the definition of rape; the structure of questions used to determine whether rape, as defined in the survey, was completed or attempted; and differences in the wording of questions designed to categorize the victim-perpetrator relationship. Univariate statistics with 95-percent confidence intervals were used for rape estimates and the rape estimates that took into account the victim-perpetrator relationship. 4 tables, 7 notes, and 32 references