A reminder that I’m shifting my output over to Substack, so it would be wonderful if you could subscribe over there. I’ve been reworking some older posts on this blog and publishing them there so you may recognise a few old favourites.
In Attention, Meaning & Mastery I wrote that all teachers need to answer four questions every lesson:
- How do all know that all students are paying attention?
- How do I know that all students have made sense of what has been taught?
- How do I know all students are mastering the skills I want them to learn?
- How can I do all this in a way which is inclusive and results in all students experiencing success?
While that post set out some strategies for answering the first 3 questions, this post aims to explore how we can address the fourth.
Why do some students struggle? The intuitive answer is that some students just don’t have the academic ability to do well at school. Compelling and obvious as this may seem, there is some cause for doubt.
The late, great New Zealand professor of education, Graham Nuthall wrote in his wonderful book, The Hidden Lives of Learners, “Ability appears to be the consequence, not the cause of differences in what students learn from their classroom experiences.” This may take a moment to parse. We tend to believe that differences in children’s ability cause some to learn more and others to learn less but what Nuthall is suggesting is that children’s academic ability is – to some extent – a product of what happens in the classroom. So what is it that occurs in classrooms that result in children becoming more able? In ‘The Curriculum as the Cause of Failure’, Siegfried Engelmann, the creator of Direct Instruction said, “The curriculum will largely determine the extent to which children are smart.”
This is an idea I explored in my book, Making Kids Cleverer. In it I argue that the single most important difference between children is the quality and quantity of what they know. This is not to discount the profound differences between children’s socio-economic backgrounds, or their relative fortune in the genetic lottery. Instead it is observe that most of the differences between children are not amenable to the actions of teachers: we cannot solve social disadvantage and have no ability to meaningfully address children’s physical or mental endowments. However, we have enormous potential to determine what children encounter in our classrooms. The quality and quantity of what children know is the area on which we can have the most impact and so is, in my view, the most important.
This leads to the following proposition: students fail to meet our expectations because we leave gaps in our teaching. The implication is that whilst students failing to make progress may not be our fault it is our responsibility. Even if this is not always and completely true, it’s a useful way to act. The alternative is to blame students for their failures and that is unlikely to result in them making the improvements we hope for. The solution I’m offering here is one I’ve come to call gapless instruction.
The idea is, quite simply to find and eliminate the gaps in our teaching in an effort to ensure all children experience success. No doubt it’s probably impossible to fill every gap between our expertise as teachers and what we what our students to be able to do, but that’s not the point: what matters is that we adport a gap-finding mentality and act as if the gaps we identify can be filled with better explanation and additional opportunities for practice.
Principles of gapless instruction
- Students’ failures are the result of gaps in instruction
- Success must precede struggle
- Aim to make practice perfect.
1. Assume students’ failures stem from gaps in teaching
What if progressing through the curriculum doesn’t result in students making progress? This is a sad reality for all too many students. Obviously there are students who’s attendance and behaviour create huge obstacle to their success but what about the diligent young people who turn up to lessons, complete the activities we set them to the best of the ability and appear to learn little. Why would this happen?
Of course there are many possible answer but the ones it most productive for us to focus on are the quality of curriculum and teaching. The curriculum is good enough if it lacks specificity, if it isn insufficiently systematic or if it pays too little attention to subject disciplines. (I’ll write more about these issues in a future post, but for now, this blog might prove a useful source.)
It is increasingly clear to me that more socially advantaged students are often successful despite what we do. They have are more likely to have the wherewithal to get the help they need to find an fill the gaps in teaching for themselves. Less socially advantaged students are only likely to be successful because of what we do. If we want to find out whether our curriculum or teaching is effective we’ll learn little from looking at the performance of the most advantaged. To really get a sense of our effectivness we must look only (or at least, look first) at how our most disadvantaged students perform. If we get instruction right for the most disadvantaged students, we will get it right for everyone.
Assessment is crucial. If you’re not assessing whether students are learning what is being taught you’re not really teaching. And, the only way to assess in such a way as to find out whether you’re teaching is effective is to use mastery assessment.
Most assessment in schools is discriminatory. It’s purpose is to discriminate between students and place them in a rank order. If you have a normal distribution of student ability, it will provide a normal distribution of outcomes. This is how SATs, GCSEs and A levels work.

The problem with this approach to assessment is that all it tells you is that some students are more fortunate than others. It’s unlikely to give you meaningful feedback about the quality of your curriculum or teaching because it’s designed to test things which not all students will be able to do.
Mastery assessment, on the other hand, judges the curriculum and its implementation, not students’ ability.

The goal is to design assessments which allow all students to get 100%. If they cannot answer a question the iference we should draw is that either we didn’t teach a concept well enough or that will allowed insufficient opportunity for practice. If you want to know how effective teaching is, students must only be assessed on whether they know and can do the things they have been taught. Sadly, testing whether students can do things they’ve not been taught top do is endemic. This is less of an issue in subjects like maths (although maths teachers often fail to explicitly teach students how to use calculators or other equipment) but is a huge issue in any subject where students’ ability is assessed through extended written responses. Unless students have been explicitly taught every aspect of how to construct these responses, all we will discover is that some students are successful despite our lack of specificity and that others are unsuccessful because of it.
Designing mastery assessments requires some explanation and will be the topic of a future post. For now, it might be useful to think abou the inferences we might draw from students’ responses to a question as a series of prompts.

It should be obvious that if no students manage to answer a question correctly then the fault is ours. This aspect of the curriculum will need to be retaught with careful thought given to the design of the instructional sequencing. But what if most students answer a question correctly? What should we do then? Well, it depends on what we mean by ‘most’. A common misreading of Rosenshine’s Principles of Instruction has resulted in many teachings being satisfied with an 80% success rate. Whilst it might make sense to look for each individual students acheiving 80%, it should be a concern if 20% – a fifth – of our students cannot do something we have taught them to do. Unless to understand ‘most’ to mean something much closer to ‘all’ then we should again acknowledge that there are gaps in our curriculum or issues with how it is being taught. We also need to be mindful that if this is the first time students have answered a question correctly there understanding is likely to shallow and transient. We should look for students to answer similar items on multiple occasions before we ccan be content to move on.
2. Success must precede struggle
The second principle of gapless instruction asks us to consider the need for students to establish a firm foundation of success before we ask them to attempt to grapple with more challenging content.
There is a vogue in some educational circles for deliberately engineering and celebrating students’ failure. The rationale is that by experiencing and overcoming failures they will become more resilient. This is, I think, to both misunderstand how resilience works as well as to lack appreciation of the necessity of having expereinced lots of success before we can contend usefully with failure. Many students’ expereince of school is of consistently and persistently failing. The often have a strongly held belief that they are unable ever to succeed. For such children further failure will only deepen their conviction that they are ‘rubbish’ at school.
As successful adults we are stategic quitters. In order focus on what we are best at we have given up on pursuing those things we have received unambiguous feedback that we are bad at. As such we can make poor role models for the students we teach.
The most important thing we can do for our students is, a quickly as possible, to give them an experience of success.

A Satnav is the perfect Assessment for Learning machine. It’s knows exactly where we are… in our learning; we tell it our goal and it gives us step by step feedback ensuring that we acehieve our goal. If we make a mistake it gives us precise feedback based on where we are right now and gets us back on track. Map reading is much more foortful and prone to user error. As most of us to prefer avoid using a map unless there is no alternative, we are much more invested in learning routes.
This serves as a useful analogy as to how we should teach students who have not yet experienced success. The drawback of a Satnav is that it is so efficient that we are less likely to expend the effort required to learn routes. Similarly, students can become dependent on their teachers. At some point we need to switch from Satnav mode to make our teaching more like map reading: instead of offering complete solutions we might suggest prompts and say things like, what did you do last time? Needless to say, switching too quickly from Satnav to map reading can backfire, but delaying too long comes with its own costs. Ultimately, students leave us only with the contents of their own long-term memory. If we fail to motivate them to internalise our instructions we will be doing them a disservice.
3. Aim to make practice perfect
There are three ways we can seek to perfect conditions of practice in our classrooms. Firstly, we need to acknowledge that practice does not make perfect, it makes permanent. What we practise we become better at. If we practise doing things badly we get better at being worse. This being the case we should strive to avoid allowing students to embed errors.
As an example, many students avoid using capital letters when writing. It’s not that they don’t understand the concept of when and how to use capital letters its that they have embedded not using them. For me, although I could, if pushed, write my name with capital letters, I’d have to concentrate as I’ve automatised the process of using capitals for proper nouns. Students are no more or less idle than I am but for them the need to concentrate works the other way because they have automatised no using capital letters. A close examination of students’ written work quickly reveals that much of the writing they do in school is poor quality. They practise writing badly day in, day out and, as a consequence, have become superb at writing badly. This is in no one’s interest. It is urgent that we redress this situation and create incentives to prevent students from practising making mistakes.
Secondly, practice should focus on doing less for longer. We tend to expect students to move on to producing more complex responses before they have mastered the basics. To use the example of writing, we expect them to write essays when they are unable to reliably construct syntactically correct sentences. By maintaining our focus on the basic s for longer we help students master the building blocks of our subjects and help ensure that when they eventually move on to more complex responses they are fluent in the basics.
Finally, we need to normalise the concept of over practice (or over learning). Too often as teachers we get students to practise a skill until they are able to do it and then move on. Instead we should continue to practise until the idea of failing becomes inconceivable.
By trying to adopt these principles of gapless instruction we are more likely to teach in a way that is inclusive and increases the likelihood that all children experience success.
To recapitulate:
- Students’ ability is the consequence of what and how we teach
- Without mastery assessment you have no idea whether instruction or curriculum is effective
- Students’ failures can help us improve both curriculum and instruction but are unlikey to be motivational for students
- Struggle should only be induced after students have experienced success
- Effective practice is focussed, corrects errors and embeds good habits
Constructive feedback is always appreciated