Mock results come home. Your child has done better than last time. Everyone relaxes a little.
That is a reasonable reaction, and most of the time it is the right one.
But there is a case where a better mock is genuinely bad news, and almost nobody warns parents about it. It is worth understanding, because the mistake is easy to make and it costs real marks in the summer.
Doing well and having learned are not the same thing
That may read like word games. Decades of laboratory work say otherwise, and the finding has held up better than almost anything else in the study of learning.
Two researchers, Robert Bjork and Nicholas Soderstrom, reviewed the evidence and made the distinction as sharply as it can be made. Performance is what you can do right now, while you are being taught or tested. Learning is what is still there weeks later, when you need it.
Their conclusion, in their own words: conditions during teaching “can have opposite effects on learning and performance.“[1]
Opposite. Not merely different. Some ways of working make a student look better now and leave them knowing less later.
And the trap closes because we cannot feel the difference. The same review notes that people “mistakenly interpret their performance during acquisition as a reliable guide to long-term learning.“[1]
In other words: it felt like it was going in. That feeling is not evidence.
What this means for a mock
Consider two students preparing for a mock in three weeks.
Student A spends the last four evenings on it. They re-read their notes repeatedly. They memorise a set of quotations and an essay structure. It is intense, and it works: they walk in with everything fresh and they do well.
Student B has been working for months in shorter sessions, coming back to the same skills repeatedly with gaps in between. They have been corrected each time. In the week before the mock they do not cram. They do a normal amount.
Student A may well score higher. Cramming genuinely works — for a test that is imminent.
The research on this is old and consistent. Studying everything in one block beats spreading it out when the test comes immediately afterwards, and loses to spreading it out when the test is delayed.[2] Spacing practice out over time is one of the most reliably repeated findings in the whole field.[3]
Now look at the calendar. The mock is in three weeks. The real exam is in six months.
Student A has optimised for the wrong date.
Why the better mock can actually make things worse
The score itself does no harm. What follows it can.
A good mock result tells a family that the current approach is working. So the current approach continues. Nobody investigates. Nobody goes looking for the specific weaknesses, because the number said there weren’t any.
Six months later the same student sits the real paper, without the fresh cram, on unseen material, and the result is a surprise to everybody.
The mock did not cause that. But it did hide it, and it bought the student six months of confidence in a method that was never building anything durable.
That is the honest version of the headline. A better mock can mean a worse GCSE, not because doing well is bad, but because a score achieved by cramming is a measurement of the cram, not of the child.
Please do not conclude that mocks are a waste of time
They are among the most useful things your child will do all year, and the research is emphatic about it.
The act of sitting a test is itself one of the most effective ways to learn. Roediger and Karpicke showed that “taking a memory test not only assesses what one knows, but also enhances later retention“, an effect so well established it has its own name, the testing effect.[4] Practice testing is consistently rated among the most effective study techniques available.[5]
So the mock is valuable. Enormously so.
The distinction is what it is valuable for:
– A mock used as retrieval practice — sit it, find out what you could not do, go and fix those things — makes a student better. – A mock used as a target to cram for — get the number up, feel reassured, move on — makes a student look better.
Same exam. Opposite outcomes. The difference is entirely in what happens in the fortnight either side of it.
What to do with a mock result
Whatever the number was, the useful questions are the same three.
1. What exactly went wrong? Not the grade — the specific things. Which question types lost the most marks? Was it running out of time, or not knowing what the question was asking, or knowing it and not being able to write it clearly? A grade cannot tell you. A breakdown can.
2. What was revised in the week before? If the answer is “a lot”, treat the score as provisional. It is measuring recent effort as much as durable skill. Nobody has cheated; that is simply what a cram measures.
3. What has been fixed since? This is the one that matters, and it is the one almost never asked. A mock that identifies four weaknesses and leads to four fixed weaknesses is worth more than a mock two grades higher that led to nothing.
The uncomfortable bit
Working the way that actually builds skill — spaced out, coming back to things, being corrected, doing it again — feels worse than cramming. It is meant to.
Researchers call these “desirable difficulties”: ways of working that slow you down and feel less productive, and produce better long-term learning precisely because of the extra effort.[6]
This is why a good programme can feel harder than a weekend of revision that felt great. The weekend that felt great was optimising for how it felt.
We would rather your child’s confidence came from a skill that is genuinely there in June than from a number in December.
If you would like a proper breakdown of where your child actually stands — the specific skills, not just a grade — our assessment takes about two minutes.
