TABLE 2.
χ 2 | κ | Symmetric Somers' d | Cramer's V | |
---|---|---|---|---|
Nicotine | 248.8 | ---- | 0.96 | 0.90 |
Alcohol | 344.1 | 0.81 | 0.99 | 0.70 |
Cannabis | 925.1 | 0.84 | 0.98 | 0.77 |
Notes: Degrees of freedom (df) for likelihood ratio χ2 test is 6 for nicotine and 9 for alcohol and cannabis; all p values < 0.001. Cohen's κ is a measure of nominal scale agreement between two categorizations of responses or ratings; it is restricted to square tables where row and column values represent the same scaling. Thus, there is no κ value for nicotine. Symmetric Somers' d is an ordinal measure of association between categorizations and indicates the proportional reduction in error from predicting the ranking of respondents in one categorization from the ranking in the other categorization. Cramer's V is a measure of association for nominal variables for use with tables greater than 2 × 2 in size.