Constructing a Universal Scale of High School Course Difficulty

Abstract

This study examined the usefulness of applying the Rasch rating scale model (Andrich, 1978) to high school grade data. ACT Assessment test scores (English, Mathematics, Reading, and Science) were used as "common items" to adjust for different grading standards in individual high school courses both within and across schools. This scaling approach yielded an ACT Assessment-adjusted high school grade point average (AA-HSGPA) that was comparable across schools, cohorts, and among students within the same school and cohort who take different courses. The AA-HSGPA was constructed for all ACT-tested students (N=36,652) in 50 selected high schools. First-year college grades at a large public university were available for approximately 1,500 of these students. AA-HSGPA was a better predictor of first-year college grade point average (CGPA) than the regular high school grade point average (HSGPA). As expected, the regression of CGPA on HSGPA for high schools grouped by difficulty with regard to grading policy (easy or hard) differed, but the regressions of CGPA on AA-HSGPA and the ACT Composite score (ACTC) did not. The best model for predicting CGPA included both the ACT Composite score and AA-HSGPA. 1 Constructing a Universal Scale of High School Course DifficultyAs a measure of academic achievement, the grade point average (GPA) is limited by the extraneous effects of schools and courses. The problem of school effects was first to be recognized. Linn (1966) noted that variation in grading practices among high schools made the high school GPA (HSGPA) a sub-optimal predictor of achievement in college. The problem of course effects has received attention more recently. Students can earn a higher grade point average simply by taking easier courses. These problems fuel grade inflation at the high school level (Ziomek and Svec, 1995), and create incentives for students to avoid courses in difficult subjects such as mathematics and science (Johnson, 1997).In an effort to improve the prediction of college GPA (CGPA) by HSGPA, a number of earlier studies attempted to adjust both the predictor and criterion grades (Bashaw, 1965;Bloom and Peters, 1961;Lindquist, 1963;Potthoff, 1964;Tucker, 1963). This approach, called "central prediction systems," was an attempt to control for school effects. Disappointment with this approach centered largely on the practical difficulties of its implementation. It was difficult to find enough students from a given high school within a given college to estimate coefficients in nested regression equations. Data for one or more variables in the equations were frequently missing for many of the students who could be found. Linn (1966) noted that the accuracy of central prediction systems often was not so much better than that of simply using a standardized test, such as the ACT Assessment, in conjunction with HSGPA, to predict college achievement as to justify the cost and expense of these systems.In an attempt to construct more reliable, predictable measures of college achievement, scali...

Study Habits, Skills, and Attitudes: The Third Pillar Supporting Collegiate Academic Performance

“…well documented in the educational literature (e.g., Bassiri & Schultz, 2003;Rubin & Stroud, 1977;Willingham, Pollack, & Lewis, 2002;Zwick & Green, 2007). Bassiri and Schultz, for example, used ACT assessment test scores to adjust HSGPA for different grading standards and showed that HSPGA adjusted in this manner predicted freshman GPA significantly better than did unadjusted HSPGA.…”

Examination of Indices of High School Performance Based on the Graded Response Model

“…The results for the GRM‐based indices are contrasted to those for HSGPA and the HSAR index. Our study can be considered an extension of the work of Bassiri and Schulz () and Hansen et al. ().…”

“…Inclusion of standardized measures like ACT test scores has the potential to illuminate differences in course difficulty across high schools (Linn, ). As in Bassiri and Schulz (), ACT test scores can serve as “common items” while parameters for coursework and grades can vary across high schools or groups of high schools. Inclusion of ACT test scores also has potential to help calibrate parameters for coursework and grades, even if the parameters are constrained to be the same across all schools.…”

“…The scaling models can also account for between‐school differences in course difficulty. For example, Bassiri and Schulz () used ACT test scores as common items across high schools to create a high school course difficulty scale using the Rasch rating scale model (Andrich, ).…”

Estimating High School GPA Weighting Parameters With a Graded Response Model

“…Similar to Young (), recent studies of course‐adjusted GPA methods have generally focused on using item response theory to correct the college grade point average or class rank for differential grading stringency across college courses and departments (Bailey, Rosenthal, & Yoon, ; Caulkins, Larkey, & Wei, ; Johnson, ; Lei, Bassiri, & Schultz, ; Young, ). An exception is Bassiri and Schultz (), who used a Rasch rating scale model to create a universal scale of high school difficulty by using ACT performance as an anchor.…”