Description

A survey of student opinion on the Vietnam War was taken at the University of North Carolina at Chapel Hill in May 1967 and published in the student newspaper. Students were asked to fill in ballot papers stating which policy out of A,B,C or D they supported. Responses were cross-classified by gender/year.

The response categories were:

A

Defeat North Vietnam by widespread bombing and land invasion

B

Maintain the present policy

C

De-escalate military activity, stop bombing and begin negotiations

D

Withdraw military forces Immediately

Usage

Format

A frequency data frame with 40 observations representing a 2 x 5 x 4 contingency table on the following 4 variables.

sex

a factor with levels Female Male

year

year of study, an ordered factor with levels Freshmen, Sophomore, Junior, Senior, Grad student

response

a factor with levels A B C D

Freq

cell frequency, a numeric vector

Details

For some analyses, it is useful to treat year as numeric, and possibly assign grad students a value year=7.

Source

Aitken, M. etal, 1989, Statistical Modelling in GLIM

References

Friendly, M. (2000), Visualizing Categorical Data, SAS Institute, Cary, NC, Example 7.9.

Examples