Categorical Regression Reference Level. A b c d. It compares each level of the categorical variable to a fixed reference level.
Note that if the order of the rows in. Say we have a study of aneurysm locations. Remember the regression coefficients will give you the difference in means andor slopes if youve included an interaction term between each other category and the reference category.
And F is a predictor in your model and you want F.
This is the default for unordered factors in R. X1 - factor rep letters 14 3 x1. By default SPSS assigns the reference group to be the level with the highest numerical value. This will select the first level of the variable in the data table.
