We take a lot of traditions for granted, and rarely think to ask questions about not only why we do something a particular way, but whether that something actually works or is good.

Take, for example, the lowly red marking pen.

Long used by teachers, professors, copyeditors and others to highlight wrong answers or problems that need correcting on a paper, a test, or something else submitted for approval, the red pen has been ubiquitous.

But red is an emotional color. People respond strongly to it, either negatively or positively. So using it can evoke unintended emotions where none are required (or worse, interfere with the feedback loop).

So does the color red interfere with feedback in the real world, when professors are grading college papers? Let’s find out.

The study of 199 undergraduate sociology students was designed with a simple objective in mind:

The purpose of our research is to investigate the effect of the color of the grading pen on student evaluations of the teaching and learning process. Research shows that the color red can create strong affect that might interfere in the communication of cognitive feedback to students.

Participants were given one of “four versions of a vignette that presents an essay question, an answer to it by a hypothetical student named Pat, comments on the essay by a hypothetical instructor, and a grade.”

Essays were either high quality or low quality, and the comments by the instructor were either in the color blue or red. Participants were then asked for their reactions after reading one of the four different essays, using five Likert-type items.

The researchers found little support for the idea that the pen color of comments mattered — except in one case. Subjects who read a high-quality essay graded in a blue pen felt the instructor likely had a better rapport with students, was enthusiastic in teaching and generally nicer than those who graded in a red pen.

The pen color had no impact, however, on subjects’ views of the instructors instrumental teaching skills — for instance, is the professor knowledgeable and organized?

The researchers did not find that grading with a red pen made the grade or comments seem more harsh. Nor did the red pen reinforce positive comments on a high-quality essay, or amplify the criticism of a weaker quality essay.

So the evidence is mixed at this stage. Previous research found some impact that red pens can make. For instance, one study found that college students posing as teachers using red grading pens resulted in more errors being found on a fictitious essay given to them to grade.

When in doubt, it’s probably best to leave your creative red side be and grade papers in a neutral color. That seems to be the safest choice, if one doesn’t want to accidentally say more than they had intended.


Dukes, R.L. & Albanesi, H. (2012). Seeing red: Quality of an essay, color of the grading pen, and student reactions to the grading process. The Social Science Journal. http://dx.doi.org/10.1016/j.soscij.2012.07.005