Plus/Minus Grading

A Presentation of the Main Arguments

Ch. Steinbruchel
Chair, Faculty Senate Curriculum Committee
February 19, 2004

The Faculty Senate Curriculum Committee, after extensive deliberation, has passed and forwarded to the Faculty Senate a resolution concerning the introduction of a new grading system at RPI which will include plus and minus grades. Arguments considered by the Faculty Senate Curriculum Committee in adopting the resolution will be summarized below. The Faculty Senate Curriculum Committee believes strongly that this new system will be of significant benefit to students.

The proposed new grading system is described in detail at the end of this report. You can also find more references there. Background information regarding +/- grading is provided in the accompanying report by J. Deery. A separate document illustrates the effect of +/- grading for different grade distributions.

Why introduce +/- grading ?

The main arguments in favor of +/- grading are the following:
  • It will allow for more precise and fairer grading.
  • It will provide a more reliable indication of student performance.
  • It will give students a better opportunity to improve their grades.

The major problem with the present grading system is that it gives a very inaccurate picture of differences between letter grades. For example, the difference between what is now a B and a C (1 grade point) may in fact be as small as 0.33 (B- vs. C+) or as large as 1.66 (B+ vs. C-). Or, to put it in another way: The difference between the lowest B and the highest C in a class now looks much bigger than it really is. Therefore, the present system is inherently unfair. The +/- system would be much fairer and thus would be a better indicator of differences in student performance.

It will also be much easier for students to improve a grade with the proposed +/- system. For example, assume that before the Final in a certain course, a student finds herself in the middle of the B's and that it would take a 98 on the Final to get an A. This may not be feasible even with a heroic effort, yet it may entirely be possible for her to get a B+ instead of just a B with a reasonable effort. In other words, with the +/- system there is a much better chance to be rewarded for a reasonable effort.

Concerns about +/- grading

  • Will there be a negative impact on student GPAs ?

The general answer to this concern is a clear no. A number of studies at other universities as well as our own data indicate that the overall impact on GPAs will be small. The faculty on the Faculty Senate Curriculum Committee regraded courses they had taught recently on the basis of the +/- system, and the data showed that in almost all courses the average of grades changed by at most a few one hundreds of a point, and not necessarily in the same direction. The only exceptions were two or three courses with very small enrollment, in which cases changing a couple of individual grades may make a bigger difference for the average grade. The same conclusions follow from looking at different types of grade distributions and the effect of +/- grading on individual grades and the class average.

The one group of students who will see a small negative impact is the straight A students under the present system. With the proposed +/- system the highest possible grade will be A, and not A+. What were A's previously will become A and A-, and therefore a straight A average may turn out to be a little lower than 4.0 under the new system. On the other hand, D students under the old system would probably see a small positive impact with the +/- system.

The Faculty Senate Curriculum Committee considered various alternatives at the top of the grade scale, such as having A+ = 4.33, or having A+ listed in the transcript but counting numerically as 4.0. The Faculty Senate Curriculum Committee eventually adopted a highest grade of A = 4.0, which is in line with what most other universities do that we compare ourselves to. In any event, there was very strong support that the overall GPA should be capped at 4.0. Most of these institutions, incidentally, have a +/- grading system in place already.

Instead of having A+ = 4.33, the Faculty Senate Curriculum Committee endorsed the notion that truly exceptional performance should be rewarded by a Certificate of Distinction. A special certificate seems to be a more meaningful sign of distinction than an A+ buried somewhere in the transcript. Such certificates can be issued already at present, and the Faculty Senate Curriculum Committee will strongly encourage faculty to make use of these certificates once the +/- system has been adopted.

  • Will there be a negative impact due to a different psychology of grading ?

It seems that the new system will in no way encourage more "bumping down" or drawing the lines between grades differently. There is no reason why the degree of arbitrariness should go up. At present arbitrariness is primarily due to differing behavior of individual instructors, not the overall grading system, and that will not change with the new system. In fact, it can be argued that a system allowing for finer grade distinctions will reduce the degree of arbitrariness.

Plus/Minus Grading: The FSCC Resolution

  1. Grade Scale:
         For undergrad. students: A, A-, B+, B, B-, C+, C, C-, D+, D; F.
         For graduate students: A, A-, B+, B, B-, C+, C; F.

  2. Numerical equivalents:
         A = 4.00, A- = 3.67, B+ = 3.33, B = 3.0, etc.

  3. Conditions for probation:
         Same as before.

  4. Graduation requirements:
         Same as before.

  5. Start of new system:
         F 04, with note in transcript.

  6. Application of new system:
         To all students: old and new, undergraduate and graduate.


a) References with data:

Report to the University Senate, University of Maryland (2003)
A fairly complete study with 4 semesters of data.

North Carolina State University summary report on the effects of +/- grading (1997)
A study with 6 semesters of data.

North Carolina State University detailed report (1997)

Wake Forest +/- grading proposal (undated, presumably 1997)
Limited amount of discussion.

Wake Forest computer model of the effect of +/- grading on GPAs (1997)

b) References with general discussion:

A brief report on plus/minus grading implementation at Arizona State University (2003, with a link to a more complete report)

Truman State report (2000) with information on plus/minus grading at Western Kentucky University

Report of the Loyola University Task Force on +/- grading (1998)

California Community Colleges report on +/- grading (1997)

Plus/minus grading at the University of Cincinnati
(including a discussion of grading options at the top of the scale; undated, circa 1994)