What is double marking – and when is it worth it?

Two pairs of eyes on every grade

Marking is a matter of professional judgement, and no single marker is entirely consistent. Double marking adds a second pair of eyes – not to a sample, as in most moderation, but to every piece of work it covers. If the two markers agree, the grade stands on firmer ground. If they disagree, the difference is caught before it reaches the student.

In the UK, double marking is common for high-stakes work such as dissertations and final-year projects. In the Nordic countries, a similar principle is built into the exam system itself: many exams are graded jointly by an internal examiner and an external examiner, or censor, who each form their own view of the work.

How does it work?

The details vary, but double marking usually involves the following:

• Two independent assessments. Each marker reads and assesses the work against the same criteria.
• Blind or open marking. In blind double marking, the second marker does not see the first marker’s grade or comments. In open double marking, they do.
• Agreeing a final grade. The markers discuss their judgements and agree a grade, or a rule decides – for example an average, rounded according to local regulations.
• A third view if needed. If the markers are far apart, a third marker or moderator reviews the work and settles the grade.

Why does double marking matter?

The main reason is reducing the impact of individual judgement. Every marker has blind spots, and a second marker can catch errors, misreadings and unusually harsh or generous judgements. For the student, it means their grade does not depend on one person alone.

It also strengthens trust in the result. A grade agreed by two markers is easier to explain and defend, and the discussion between markers helps build a shared understanding of standards over time.

What double marking cannot do

Double marking does not guarantee agreement. Research has repeatedly found that markers often disagree – sometimes widely – especially on open, essay-type work. Two markers can reduce the effect of one person’s judgement, but they cannot remove subjectivity altogether.

Blind and open marking also have trade-offs. Studies suggest markers agree more when they can see each other’s marks – but that may partly be because the second marker is influenced by the first. Blind marking gives a more independent view, but needs more time to reconcile. And double marking is costly: it roughly doubles the marking effort, which is why many institutions reserve it for the assessments where the stakes are highest.

How does WISEflow approach it?

In WISEflow, double marking is part of how a flow is set up, not something coordinated by email. Our understanding goes a little further than adding a second marker:

• Several assessors on the same work. Two or more assessors – internal or external – can be allocated to each submission.
• Blind or open, as the institution chooses. Assessor types determine whether markers can see each other’s grades and feedback, so both blind and open double marking are supported.
• Disagreements handled clearly. WISEflow can suggest a final grade based on the assessors’ grades – for example the average – and a reviewer or the assessors decide the final grade.
• Anonymous where it matters. Double marking can be combined with anonymous marking, so neither marker knows whose work they are reading.
• A full audit trail. Each assessor’s grade, any disagreements and the final decision are recorded.

What should institutions consider?

• Where to use it: reserve full double marking for high-stakes work, and use moderation for the rest.
• Blind or open: choose deliberately, based on the purpose and the time available.
• Resolution rules: agree in advance how disagreements are settled, and when a third marker is needed.
• Calibration: clear criteria and a shared rubric make agreement more likely from the start.

Double marking is not a cure for subjectivity. Used well, as part of a considered approach to marking and moderation, it makes every grade less dependent on one person – and more worthy of trust.