PLUS-MINUS GRADING: Impacts on
Grading at UNCA
Report of the Academic Policies Committee Jeff Konz, Chair
Last fall, the Executive Committee asked APC to conduct an assessment of plus-minus grading since its introduction at UNCA in 2002-03. The questions and issues that we hoped to address were as follows:
--Usage: How many faculty members are actually using +/-? Are there differences across departments? Overall, what proportion of grades is +/-?
--Impact on grade distribution: Does +/- result in grade inflation? Does +/- result in grade compression?
--Equity: When there are multiple sections of the same class, has +/- grading widened or narrowed the distribution of grades in multiple section courses? Are there significant differences in usage across departments and programs? Has +/- grading had different systematic impacts on students with different GPAs? Ought we expect all faculty members to use +/- grading, or is this an issue of faculty autonomy?
To address these issues, we undertook two activities. First, we surveyed the literature on grading to see if there are any systematic impacts of plus/minus grading at institutions that have transitioned from straight letter grades to plus/minus grading. Second, with the assistance of Institutional Research, we looked at UNCA faculty grading before and after we switched to plus/minus grading to determine if there is any recognizable impact on student grades.
The literature review, conducted by Mike Ruiz and Linda Cornett, showed that, broadly speaking, there was little expected or actual impact of plus-minus grading on grade distributions. In particular, they found that there was no discernable impact on grade inflation. The only students who would be expected to experience an impact would be those at the upper end of the grade distribution, because of the existence of A- grades without A+ grades.
They also found that the concerns that faculty have at other institutions are similar to the concerns that faculty have here—about the impact on grade inflation (which, again, appears to be minimal at most) and about equity, particularly uneven implementation of +/- grading in multiple-section courses.
In summary, other institutions have found little impact from +/- grading on the grade distribution.
The data which we requested from Institutional Research led
us to the following conclusions:
Usage:
--During the first two years of
plus/minus grading at UNCA (AY 2002-03 and 2003-04), 84.2% of full-time regular
UNCA faculty used plus/minus grading. Only
three faculty members granted either plus or minus grades
but not both.
--Of 25 departments/programs with full-time regular faculty, 10 have 100% plus/minus grading, and 22 have 75% or more. The lowest utilization is in a department which has 30% of faculty members using plus/minus grading, a significantly lower proportion than any other. However, with the exception of that department, there is broad consistency in the rate of utilization of plus/minus grading across departments and programs.
--In 2003-04, 29.1% of grades were either
plus or minus; in 2002-03, 25.1%.
Impact on Grade
Distribution:
--Grade Averages: If we assume that without plus/minus grading, both plusses and minuses revert to the base letter grade (i.e., a student who receives an A- would have received an A, and a student who receives a B+ would have received a B), the collective UNCA GPA is .02 points lower with plus/minus grading than it would have been with straight letter grading. This difference is the same in both 2002-03 and 2003-04. We consider this difference to be trivial.
--Grade Compression: Has plus/minus grading pushed the
distribution of grades closer to the mean, which is
approximately 3.0? Again assuming that
without plus/minus grading, both plusses and minuses revert to the base letter
grades, A-, C+, and D+ grades move grades toward the mean, while B+, B-, and C-
grades push grades away from the mean. In
2003-04, 14.0% of grades were A-/C+/D+, and 14.9% were B+/B-/C-. In 2002-03, these percentages were 12.5% and
13.6%, respectively. As a result, the
variance of grades is slightly higher with plus/minus grading than without.
Equity:
--As noted, with the exception of one department, there are not significant differences in the usage of plus/minus grading across departments, and therefore no equity issues for students of different majors.
--In looking at grades given in courses with multiple sections, APC observes that there are significant differences across courses, but not as a consequence of some instructors using plus/minus grading and some not. There appears to be no connection between grading policy and course GPA, and therefore no equity issue for students. We are concerned about the significant difference in grades across sections in these courses, but view this as a matter for Chair and Program Director discretion.
--We note that while the mean GPA is trivially lower with plus/minus grading, there is a larger impact on students at the top of the grade distribution than others, because of the existence of A- grades but not A+ grades. However, this can be seen as a consequence of greater accuracy in grading, and the ability to distinguish between A and A- work, and not a result of unfairness in switching to plus/minus grades. This result is not unexpected; it was anticipated in the 2000 Senate debate about instituting plus/minus grades and was found by other institutions making a similar transition. We do not see this impact as an issue of equity.
--Finally, we do not advocate a policy
which requires all faculty members to use plus/minus grades in their
courses. There are no significant
impacts of plus/minus grading which provide compelling reasons for us to
override faculty autonomy in this area.