The nod is not evidence. It never was.
Why the nod lies
Three things are happening when thirty heads go down and up at once, and none of them is comprehension.
Nobody wants to be the one who says no. Asking "does that make sense?" in front of twenty-nine other people is a social question wearing a learning question's clothes. The honest answer costs something, and the dishonest one is free.
You asked about the lesson, not about them. A pupil can follow every word you said and still be unable to do the thing you want them to do. Understanding a demonstration and being able to reproduce it are different skills, and only one of them shows up in a nod.
The pupils you most need to hear from are the least likely to speak. When you're genuinely lost, you often don't know what to ask. The ones who ask questions are usually the ones who are nearly there.
Self-assessment is unreliable at the best of times. For a fourteen-year-old in front of their mates, it is close to worthless.
Why marking the books doesn't solve it either
You can find out exactly who understood, of course. Mark thirty books and you'll know. The trouble is that by the time you know, it's Thursday.
The whole point of checking understanding is that you can still do something about it. Feedback that arrives three days later is a report on a lesson that has already been left behind. Useful for reports. Useless for teaching.
The three things a real check needs
Strip away the method and any check worth doing has the same three properties:
- Everyone answers. Not the six who always put their hand up. Hands up tells you about the six.
- You see it per pupil. A class average of 68% tells you nothing actionable. Which six are the 68%?
- It is quick enough that you will actually do it. A check you skip on a busy Tuesday is not a system, it's an intention.
The four questions worth asking
Most checking fails at the question, not the method. "Do you understand?" is unanswerable. So is "any questions?" So is anything a pupil can answer by reading the board back to you.
Ask things they can only answer if they genuinely get it:
- Give them a wrong answer and ask what's wrong with it. Spotting an error takes more understanding than producing a correct answer, and it can't be done by recall.
- Ask for the next step, not the final answer. Getting to the end can be done by pattern-matching. Knowing what to do first cannot.
- Ask why, not what. "What is the answer" is a memory question. "Why is that the answer" is a thinking question.
- Give two plausible options and make them choose. A yes/no question has a fifty per cent floor and a very high guess rate. A good distractor catches the specific misconception you're worried about.
Avoid recall of a definition, anything copied from the board, and anything with a one in two chance of being right by luck.
What to do with the answer
This is the part people get wrong. A check is not a score. It is a routing decision.
- Got it. Move on — and use them. Ask one of them to explain it to someone who hasn't.
- Shaky. They followed you but can't yet do it alone. One more example, worked through differently to the way you did it the first time.
- Lost. This is the important group, and the one a class average hides. They have usually missed something earlier, not something in this lesson. Finding them in the same lesson is worth more than anything else you do that day.
Reteaching two minutes after the check lands completely differently to reteaching it at the start of the next lesson, when half the class has forgotten the question.
The two-minute version
One question on the board. A code the class types into their phones — no accounts, no app, no logins to lose. You watch the names come in, colour-coded, and you know before the bell who needs you tomorrow and who needs you now.
That's it. The method is not clever. It's just that for once the answer arrives while you can still use it.
Questions people ask
How do you know if students understood the lesson?
Not by asking 'does that make sense?' - pupils nod to end the question, not to confirm they understood. You need them to explain it back in their own words, or apply it one step further, which is much harder to fake than a nod.
Why doesn't marking books tell you who understood?
Marking books tells you what was written, often hours or days later, when it's too late to reteach that lesson. It also can't tell you whether the pupil understood it themselves or copied a method from a neighbour.
What questions should I ask to check understanding?
Ask pupils to explain it in their own words, apply it to a new example, spot the mistake in a wrong answer, or state the next step rather than the final answer. All four are much harder to bluff than a direct recall question.
What is a quick way to check the whole class understood?
A two-minute check where every pupil answers individually - not a show of hands, not a few pupils answering aloud. Get It? runs this as a short AI-led chat, so you get a green/amber/red view of the whole class in the time it takes to pack up.
Try it on one class.
One lesson. One question. Two minutes. If it doesn't tell you something you didn't already know, walk away.
Try it free — no cardStudents need no account. They just need the code.
Read next
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How to spot the pupils who are quietly faking it
The echo, the confident wrong answer, the shrug with a smile. Six tells that a pupil has no idea, and three questions that flush it out without embarrassing anyone.