Descriptive Study of Bivariate Data 二元資料簡介
10 歲大的兒童中, 每天平均碳水化合物與蛋白質的攝取量之間的關係
Bivariate Categorical Data
When two traits are observed for the individual sampling units and each trait is recorded in some qualitative categories, the resulting data can be summarized in the form of a two-way frequency table. The categories for one trait are marked along the left margin, those for the other along the upper margin, and the frequency counts recorded in the cells. Data in this summary form are commonly called cross-classified or cross-tabulated data. In statistical terminology, they are also called contingency tables.
For this purpose, we divide each cell frequency by the sample size 400. The relative frequencies (for instance, 84/400=.21) are shown in Table 2.
From the calculations in Table 3, it appears that the attitude patterns are different between the two groups - support seems to be stronger among union members than nonmembers.