In 1968, Dr. Benjamin Spock was tried in Boston on charges of conspiring to violate the Selective Service Act by encouraging young men to resist being drafted into military service for Vietnam. The defence in the case challenged the method of jury selection claiming that women were underrepresented. Boston juries are selected in three stages. First 300 names are selected at random from the City Directory, then a venire of 30 or more jurors is selected from the initial list of 300 and finally, an actual jury is selected from the venire in a nonrandom process allowing each side to exclude certain jurors. There was one woman on the venire and no women on the final list. The defence argued that the judge in the trial had a history of venires in which women were systematically underrepresented and compared the judge's recent venires with the venires of six other Boston area district judges.
A data frame with 46 observations on the following 2 variables.
is the percent of women on the venire's of the Spock trial judge and 6 other Boston area judges
a factor with levels
Ramsey, F.L. and Schafer, D.W. (2002). The Statistical Sleuth: A Course in Methods of Data Analysis (2nd ed), Duxbury.
Zeisel, H. and Kalven, H. Jr. (1972). Parking Tickets and Missing Women: Statistics and the Law in Tanur, J.M. et al. (eds.) Statistics: A Guide to the Unknown, Holden-Day.
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str(case0502) boxplot(Percent~Judge, data=case0502, xlab="Judge",ylab="Percentage of Women") percent.spocks <- subset(case0502, Judge == "Spock's", Percent) percent.others <- subset(case0502, Judge != "Spock's", Percent) t.test( percent.spocks,percent.others) summary(aov(Percent~Judge, case0502, subset = Judge != "Spock's")) #as in Display 5.10 summary(aov(Percent~Judge, case0502))