Normalized Response Filter Expression Enter the appropriate SAS logical expression for filtering single responses based on normalized values in the output data set. For example, assuming that normalized responses are on the log2 scale, typing (response < -7.5) omits all observations that have a normalized response less than -7.5. This filter is applied after fitting the ANOVA model. To Specify a Normalized Response Filter Expression: Type the expression in the text box. If you change your mind and would like to reset the field, click Clear.