One of the first things I heard as a young teacher was that "the person doing the work is the person doing the learning." It's catchy. And it's the foundation of the peer-marking craze that's swept through schools everywhere. The idea is simple: get students to mark each other's work instead of doing it all yourself.
The two camps
The progressive side sees peer marking as empowering. Students learn to identify success criteria by looking at someone else's work. They build agency. They become independent learners.
The old-school side sees it as a shortcut. A way for teachers to avoid taking a heavy bag of books home. Lazy, basically.
What the policy wonks miss
The educational establishment is almost universally in favour of peer marking. They speak beautifully about "metacognition" and "student agency." They treat it as an unalloyed good.
But sitting in a classroom in Shanghai on a Wednesday afternoon, the reality is much messier. Most policymakers assume students are honest and objective. In reality, they're biased, confused, and often just want to get to the end of the lesson.
My take
Peer marking is a brilliant teaching tool. But it's a terrible marking tool.
If you use it to generate a grade or save yourself time, you're failing your students. But if you use it to teach them how to think like a marker — how to spot what works and what doesn't — it's genuinely useful. The goal isn't a score in a spreadsheet. It's that moment of clarity when a student finally sees why a piece of work succeeded or failed.
Why it usually goes wrong
The blind leading the blind. If a student hasn't mastered the concept themselves, they can't possibly judge whether their peer has. Without an extremely specific rubric, peer marking turns into "I think this looks good." Which is useless.
Social dynamics. Teenagers are social creatures. Ask a 14-year-old to mark their best friend's work and they'll either mark too generously to stay popular, or too harshly if there's a rivalry. The "objective marker" doesn't exist in a classroom full of teenagers.
How to make it actually work
If you want peer marking to be useful, you have to be rigorous:
Never use it for final grades. Peer marking is formative. Use it during the draft stage, never for a final score.
Check the checker. I always mark a random sample of the peer-marked work. If the student marker was inaccurate, they redo it. It keeps everyone honest.
Be specific. Don't ask students to mark "the whole essay." Ask them to mark just the topic sentences. Specificity is the only way around a lack of expertise.
The bottom line
Peer marking isn't a shortcut. Done properly, it's actually more work than marking yourself. But the payoff isn't a grade. It's a student who finally understands the "why" behind the "what."