Picture an ordinary lesson change. The bell goes. Most of the class arrives more or less on time, and two or three drift in a few minutes later. The teacher waits, because starting twice is worse than starting late. Bags come off, books come out, someone needs a pen.
By the time the room is ready to learn, four or five minutes have gone.
Nothing in that scene is a scandal. No child was rude. No teacher did anything wrong. But run it again at the next lesson change, and the one after that, five or six times a day, and the arithmetic turns serious. Twenty-five minutes a day is more than two hours a week. Over a school year it runs into weeks of teaching.
Almost no parent ever sees this happening, and it may be the single biggest difference between one school and another.
The school that decided to count it
Michaela Community School sits in Brent, one of the poorer boroughs of London. Between a third and two fifths of its pupils are eligible for free school meals.[1] Around half attract the pupil premium, the extra money given to schools for children from disadvantaged homes. It does not select by ability.
In 2025, over 80% of all its GCSE grades were 7 to 9. More than four in ten pupils walked away with five or more grade 9s, and every single pupil passed both English and Maths.[1] Ofsted has rated the school Outstanding twice, in 2017 and again in 2023, describing behaviour there as “exemplary”.[2]
The obvious reaction is that the school must be quietly choosing clever children. There is a measure designed to test precisely that suspicion, and it rules it out.
Progress 8 compares every pupil’s GCSE results with the results of pupils across England who had the same score at the end of primary school.[3] It is a measure of distance travelled rather than of where a child started. A school full of high-attaining eleven-year-olds gets no credit for their high grades at sixteen, because those grades were already expected.
The last year this could be measured was 2024. Michaela’s Progress 8 came out at 2.55, the highest in the country for the third year running.[1] The Department for Education confirms separately that the school’s admissions policy is non-selective.[3]
Whatever is producing that, it happens after the children arrive.
One honest note about the year. Progress 8 cannot be calculated for 2025, at Michaela or anywhere else, because that cohort never sat their Key Stage 2 tests — those were cancelled during the pandemic, so there is no starting point to measure from.[3] The 2025 grades above are real. The proof that they were not simply bought with a clever intake comes from 2024.
What they actually changed
The school is well known for one visible habit. Pupils move between lessons in silent, orderly lines.
It sounds severe when written down, and it attracts a lot of argument. The reasoning behind it is duller than the argument suggests. If a class arrives together and settled, teaching starts at once. Nobody is waiting. Nobody is repeating the first instruction for the three pupils who missed it. The four minutes at the front of the lesson stop disappearing.
There is an important word in how the school describes this, and it changes the meaning: the behaviours are taught. Pupils are shown what the routine looks like, they practise it, and they are corrected when it slips, in the same way they would be corrected on a piece of algebra. The Australian Education Research Organisation, reviewing the evidence on classroom routines, puts it plainly: routines that pupils know well “reduce interruptions and increase teaching time”, and explicitly teaching and modelling them frees up a pupil’s working memory to spend on the actual lesson.[4]
That is a very different proposition from being tough on children. One punishes the absence of a behaviour. The other teaches the behaviour in the first place.
This has been known for fifty years
None of it originates with any one school. In 1970, an American researcher named Jacob Kounin filmed 49 classrooms for a full day each and coded whether pupils were working, every twelve seconds.[5] They were primary classrooms, which is worth saying plainly — but what he found has been repeated in secondary classrooms many times since.
He expected to find that the best teachers were the ones who dealt with misbehaviour most effectively. He found something else. What separated the strongest classrooms from the weakest was momentum — starting activities promptly, keeping them moving, finishing them cleanly — and smoothness, meaning the absence of jolts that break the flow of a lesson. Transitions between activities turned out to be one of the main places where classrooms were won or lost.
Since then the finding has been measured many times over. Improving how a classroom is managed carries an effect size of about 0.52,[6] which is roughly the difference between an average pupil and one at the seventieth percentile.
And there is a distinction inside that research which matters more to a parent than anything else in this article.
Researchers separate allocated time — the hours a subject appears on the timetable — from engaged time, the minutes a pupil is genuinely working. Allocated time turns out to predict achievement only weakly. Engaged time predicts it strongly. Taken together, these time measures are described in the literature as the most powerful explanation of differences in achievement once you have accounted for where pupils started.[7]
Hours in a classroom, on their own, buy remarkably little. Minutes spent actually working buy a great deal.
The other half: being present without being there
Lost minutes are not only lost at the door.
A student can be sitting in the right room, at the right desk, with the right book open, and still be somewhere else entirely. Every teacher recognises it. What is less well known is how much it costs, and how precisely it has been measured.
In one study, students who used a laptop for other things during a lecture scored 11% lower on the test afterwards. Students who were merely sitting in view of someone else doing it scored 17% lower — worse than the people doing the distracting.[8] A wandering attention spreads to the desks around it.
A larger study followed 507 students through a course and tracked their non-academic internet use. It predicted their final exam score even after the researchers accounted for how intelligent and how motivated those students were.[9] Using the internet for the class itself made no difference either way.
This is engaged time again. The student is present, counted and marked on the register. Very little is going in.
Two things must be said honestly
First, the obvious conclusion about phones does not survive checking, and we would rather tell you that than let you act on it. An early English study suggested that schools banning phones saw test scores rise. A Swedish replication found no such effect, and a large 2025 study of over 1,200 teenagers across 30 schools found no difference in English or maths results between schools that ban phones and schools that do not.[10] School-wide bans are a much weaker lever than people assume. A phone in front of one working student is a different question, and there the evidence is strong.
Second, one school proves nothing on its own. Michaela offers a narrower range of subjects than most schools, which is a genuine trade-off, and entry to its sixth form is selective. The weight in this article is carried by the research, not by the school. The school is simply the clearest existing demonstration that a disadvantaged intake does not settle the outcome.
What this means at home
The transferable part is not the silence or the lines. It is the removal of the daily negotiation.
At Michaela, no pupil arrives at a lesson wondering whether today is a working day, or how long they will get before the teacher gives up. The question has already been answered, so no energy goes into asking it.
Revision at home usually goes the other way. Whether work happens, when it starts and how long it lasts are all reopened every evening, and the negotiation itself eats the time. A fixed hour, in a fixed place, with the phone in another room, removes the argument before it starts. The research above does not tell you how to parent, and it is not our business to. It does say clearly which variable is doing the work: not the total time set aside, but the minutes genuinely spent working.
GCSE English punishes the difference more than most subjects. Maths gives instant feedback, because a wrong answer refuses to balance. English does not. An hour spent reading a set text with a phone face-up produces a warm feeling of having revised, some highlighted pages, and almost no change in what a student can write under timed conditions. Nothing signals that the hour was wasted.
Which is why our programme is built on rhythm rather than good intentions. Lessons run at the same time each week. Written work is marked against the examiner’s criteria every week, not once a term. Every student knows what they are working on next, because it was decided from their last piece of marking rather than negotiated on the night.
Engaged time, arranged in advance.
