The National Youth Survey collected a sample of 11 to 17 year olds - 117 boys and 120 girls - asking questions about marijuana usage.
data(potuse)A data frame with 486 observations on the following 7 variables.
sex1=Male, 2=Female
year.761=never used, 2=used no more than once a month, 3=used more than once a month in 1976
year.771=never used, 2=used no more than once a month, 3=used more than once a month in 1977
year.781=never used, 2=used no more than once a month, 3=used more than once a month in 1978
year.791=never used, 2=used no more than once a month, 3=used more than once a month in 1979
year.801=never used, 2=used no more than once a month, 3=used more than once a month in 1980
countNumber of cases in this category
Lang J., McDonald, J and Smith P. (1999) "Association-Marginal Modeling of Mutlivariate Categorical Responses: A Maximum Likelihood Approach" JASA 94, 1161-