Marking in Red Pens Hinders Retrieval Practice

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Marking In Red Pen


Ross Morrison McGill founded @TeacherToolkit in 2010, and today, he is one of the 'most followed educators'on social media in the world. In 2015, he was nominated as one of the '500 Most Influential People in Britain' by The Sunday Times as a result of...
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What impact does the colour red have on a student’s ability to encode and retrieve declarative knowledge?

I have had a temporary respite from the final edits of my new book and using my doctoral research platforms, I have been taking a closer look at research interests, gaining full access to many research papers and journals. I have discovered this beauty … The effect of the colour red on encoding and retrieval of declarative knowledge by Gnambs, Appel and Kaspar, 2015.

The context

First, the good news. It’s a short seven-page paper which is a study on the colour psychology of teachers using a red pen when marking students work, and how it may impair cognitive performance in achievement situations. One hundred and ninety students (126 girls/= aged 16) in a secondary school were asked to memorise a short text (encoding) and will then given a knowledge test and a measure of cognitive load (retrieval).

The hypothesis was that for male students, repeated exposure to red pen would result in poorer test performance when compared to boys tested in other conditions (grey pen), whereas female students did not show any differences in testing.

The findings

The research manipulated the differences between red versus grey of stimulus material during both the encoding and retrieval phase. The findings suggested that for boys, repeated colour exposure affected their test performances more strongly than a single phase of colour. For girls, a single colour impaired knowledge retrieval compared to repeated exposure of red had no effect.

The details

The Effects of Red Pen on PerformanceColoured pens are used for aesthetic reasons, which carry psychological meaning and in some other schools I have visited, used for consistency and compliance. On my travels to schools across the country, I have even been to one school which insists that all their teachers use an ‘aqua’ coloured pen. I don’t think I’ve ever used an aqua coloured pen in my entire teaching career – and I’m a graphics teacher.

“In educational settings, recent research has shown that the colour red impairs cognitive performance in challenging tasks (e.g., Elliot, Maier, Moller, Friedman, & Meinhardt, 2007; Gnambs, Appel, & Batinic, 2010; Ioan et al., 2007; Shi, Zhang, & Jiang, 2015).”

The colour red stimulates and avoidance motivation that in turn, hampers performance in tasks that require intelligent thinking, creativity, or both. interestingly, this research suggests “that gender differences in the effects of red colour on learning and the role of cognitive load as a mediator” do play a factor.


Environment matters

Memory performance was better when the environment during encoding and the environment during retrieval were similar. On my travels, I always advocate to the schools in which I work, particularly when testing key stage 3 students, that all students are tested in the same conditions, not just in core subjects, sat in an examination hall whilst every other subject has to conducts the same end of key stage assessments in their classrooms because the school hall cannot be used for any length of time (because it would impact on PE facilities more than it needed to). If this happens, pupils will treat those tests differently and their performances will be affected.

This is why we cannot truly rely on PISA tests.

Gender and cultural differences

In this paper, previous studies are mentioned which found a stronger effect on the colour red on male rather than female participants. “On the one hand, red acts as a sign of danger and a trigger of avoidance motivation in achievement situations (Maier et al., 2008). Females scored higher on avoidance motivation than men …

“In many Western societies, reddish colours are associated with girls in dark colours (e.g. brown, black, grey and blue) are associated with boys. (cf. Boyatzis & Varghese, 1994)” we just need to look at the colours manufacturers use with toys or when you ‘Google’ using simple search terms “toys for boys“.

“Hurlbert and Ling (2007) found cross-cultural gender differences in participants’ colour preferences indicating some biological origin” but the repeated presentation of red distorts perception in boys but not in girls, which “indicates a difference in emotional valence of red”

  • For boys, red during the encoding and retrieval phase impairs test performance more strongly than a control condition with grey colour.
  • For girls, red colour cues during the encoding and retrieval phase did not impair test performance as compared to a control condition with grey colour.

Marking in red pen

Declarative Knowledge

The research (knowledge test) contained 20 open-ended questions on mediaeval dining customs. The material was handed out in a booklet form of three pages and the red and grey colour manipulation took place for half the students. For example, the title “The Medievals” was printed in a red rectangle on the first page. The control group received the knowledge test with grey colour cues. Other than the colour manipulation, the knowledge test was identical in both conditions and the sum of correct answers was the measure of declarative knowledge.

M = 12.04 (SD = 4.66) and a reliability of 0.92.

Cognitive Load

Cognitive load was measured using a computer numeric stroop task. Students were asked during the test and as quickly as possible, which number the larger value by pressing one of the two keys on a keyboard. Some were presented in large or small font with two single digit numbers (e.g. 3 or 4).

There were 32 trials and response time in milliseconds was the variable of interest. As expected, stimulus- congruent trials performed significantly lower than stimulus-  incongruent trials. Within the paper, you can find all the results.


A number of studies have demonstrated that the colour red impairs performance in intellectual tasks. research on environmental context-dependent memory suggests that repeated use of the same colour can contribute to better memory; therefore, colour manipulation the stages of encoding and retrieval might have an interactive influence on learning.

In my opinion, during the revision. Use the same coloured pen as you have always used, or introduce the colour red much earlier into the academic year.

“This research highlights the need for future longitudinal research that examine habituation and amplification effects of the color red on cognitive performance in more detail.” You will need to access the paper to read the full findings, methodology and procedures used. Please go beyond this blog and do not assume that red pens should be banned, however, it’s something worth thinking about.

Further reading: There is an interesting paper here on the quality of an essay, colour of the grading pen and student reactions to the grading process.

4 thoughts on “Marking in Red Pens Hinders Retrieval Practice

    1. Was just thinking that. Boys or males with colour blindness, mainly see red as a shade of grey. That’s the most common symptom

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