The Degrees of Reading Power (DRP) test provides DRP scores that can be matched to the difficulty of materials in order to select textbooks at the instructional level. However, the DRP test scores appear to provide invalid units for matching material difficulty. These original DRP test scores, called DRP-Ability or OldDRP scores, have been rescaled into NewDRP scores so that they are more valid for selecting instructional level materials. The OldDRP scores indicated large mismatches between the average difficulty of the books used in each grade and the average ability of students in that grade whereas the NewDRP scores indicated a very small mismatch; the average of the absolute sizes of the mismatches in Grades 4–12 was 7.4 in OldDRP units but only 1.2 in NewDRP units. These NewDRP scores have also been given in grade equivalent (GE) units, called NewDRP-GE. It was found that the average NewDRP-GE scores in each grade closely matched that grade, thus adding to the validity of these rescaled scores. When the original DRP test scores, OldDRP, are rescaled into NewDRP and NewDRP-GE units, they provide scores that seem to be valid for selecting materials at the instructional level. © 1990, SAGE Publications. All rights reserved.
