Finkelhor (1986) notes that in a study of a group of CSA survivors, many members of the comparison group may themselves have been similarly traumatized, even though they were not victims of CSA per se. Consequently, the statistically reliable differences between the two groups can be misleadingly sparse in number and small in size. To lessen the problem of overlapping traumas, this paper proposes a new type of comparison group. The proposed "No Sexual Trauma Comparison Group" excludes women who have experienced, as an adult, a sexual trauma whose impact is similar to that of CSA; it excludes victims of adult sexual abuse. In an illustrative study, the authors hypothesized that the characteristics of the CSA Group should be highlighted more when they are compared to the No Sexual Trauma Group than when compared to the Entire Comparison Group. The study reanalyzed data from an unpublished study (Hyland, 1991). Hyland's study used a 4-page questionnaire that was mailed to 2,129 undergraduate women at the Claremont College. As expected, the results were much stronger when the CSA Group was compared to the No Sexual Trauma Group. Of the five univariate ANOVA's, three were significant. Although the authors do not advocate that researchers use only No Sexual Trauma Comparison Groups, they do advise that researchers should think carefully about whether or not to use a No Sexual Trauma Group, an Entire Comparison Group, or both, due to features such as sensitivity and stability of definition. 7 references