Kleck's estimates were based on a national survey of 1,228 registered voters; 4 percent of the respondents answered that they or a household member had used a handgun protectively within the previous 5 years. These figures were expanded to obtain a national estimate. The NCVS figures included all attempted or completed incidents of victimization and were based on a large and well-documented probability sample of the U.S. The differences between the two estimates suggest that several statistical biases should be considered, namely the NCVS omissions of commercial robberies and unreported crimes, particularly those committed by non- strangers. The NCVS estimates show that, while civilian firearm use should not be disregarded as a form of crime control, the incidence of self-defensive gun use is much lower than commonly assumed. However, the authors note that this research did not address the issues of gun resistance and deterrence. 4 tables, 7 notes, and 31 references