Quantile Level for Quantile Regression Use the text field to specify a quantile level for the regression. 0.5 is set by default. You can specify any number of quantile levels between 0 and 1. If you do not specify this option, the median regression effect selection will be applied that corresponds to a Quantile Level of 0.5. To Specify a New Quantile Level for the Quantile Regression: Highlight the default value and type the desired value in the text field.