In observational studies, regression coefficients for categorical regressors are overwhelmingly presented in terms of contrasts with a reference category. For unordered regressors with many categories, however, this approach often focuses on contrasting different pairs of categories to one another with little substantive rationale for foregrounding some comparisons with others. Mean contrasts, which compare categories with the overall mean, provide an alternative to the reference category, but the magnitude of mean contrasts is conflated with the relative sizes of the categories. Instead, binary contrasts compare a category with all the other categories, allowing the familiar interpretation for dichotomous regressors. Our command binarycontrast computes binary contrasts.

在观察性研究中，分类回归变量的回归系数绝大多数是根据与参考类别的对比来呈现的。然而，对于具有许多类别的无序回归量，这种方法通常侧重于将不同的类别对相互对比，几乎没有实质性的理由来突出与其他类别的一些比较。将类别与总体平均值进行比较的均值对比提供了参考类别的替代方案，但均值对比的大小与类别的相对大小混为一谈。相反，二元对比将一个类别与所有其他类别进行比较，从而允许对二分回归量进行熟悉的解释。我们的命令binarycontrast计算二进制对比度。