The Curse of Knowledge

2 hours ago

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Building Powerful Subject Knowledge – ECF Section 3: Subject and Curriculum

“Once something becomes obvious to us, it’s surprisingly difficult to remember when it wasn’t.”

When expertise becomes an obstacle

There are moments in teaching when you explain something, ask a question or demonstrate a process and genuinely cannot understand why pupils are struggling.

You've explained it clearly. You've demonstrated the steps. You've even provided an example.

And yet, the understanding you expected simply isn't there.

It's tempting to conclude that pupils weren't listening, haven't remembered previous learning or aren't concentrating sufficiently.

Sometimes, of course, those things may contribute.

But there's another possibility worth considering.

What if the problem is that we know too much?

As teachers, we spend years developing increasingly sophisticated subject knowledge. Concepts become familiar, processes become automatic and connections that once required considerable thought begin to feel instinctive.

This expertise is essential to effective teaching.

However, it can also make it surprisingly difficult to recognise what pupils don't yet know.

Welcome to the curse of knowledge.

What is the curse of knowledge?

The term curse of knowledge was explored by economists Colin Camerer, George Loewenstein and Martin Weber (1989), who investigated how possessing information can influence our ability to predict the judgements of people who don't possess it.

Put simply, once we know something, it becomes difficult to imagine not knowing it.

Although their research wasn't specifically about classroom teaching, the concept has important educational implications.

Consider a teacher explaining how to construct a database query.

To an experienced Computer Science teacher, a statement such as:

SELECT Name FROM Students WHERE Age > 16;

might seem entirely straightforward.

But a novice learner needs to understand several things simultaneously.

What is a database table? What is a field? What does SELECT mean? Why is FROM necessary? How does the condition following WHERE work? Why are some words capitalised? What is the purpose of the semicolon?

The teacher sees one familiar instruction.

The pupil sees an unfamiliar collection of symbols, vocabulary and rules.

The difficulty isn't necessarily the complexity of the final task. It's the amount of knowledge required to make sense of it.

Novices and experts think differently

Research by Chi, Feltovich and Glaser (1981) demonstrated important differences in how experts and novices categorise physics problems.

Experts tended to recognise underlying principles, while novices were more likely to focus on surface features.

This distinction matters enormously in the classroom.

An experienced mathematician recognises that two differently worded problems require the same underlying procedure.

A novice may see two completely unrelated questions.

An experienced English teacher can recognise how a writer's structural choices influence meaning.

A novice may identify individual techniques without understanding how they contribute to the text as a whole.

An experienced Business teacher might immediately recognise the relationship between pricing decisions, market positioning and profitability.

A novice may treat these as three separate topics.

Expertise allows us to organise information into meaningful patterns.

But those patterns have been constructed over time.

We cannot assume pupils already possess them.

Making invisible thinking visible

One particularly useful response to the curse of knowledge is to make our thinking explicit.

Collins, Brown and Newman (1989) explored cognitive apprenticeship, an approach in which learners develop expertise through processes including modelling, coaching, scaffolding and gradually increasing independence.

An important element is making thinking processes visible.

In practical terms, this means demonstrating not only what we do, but also how we decide what to do.

Imagine teaching pupils to evaluate a business decision.

Rather than simply presenting a model paragraph, I might narrate my thinking:

"I'm being asked whether this business should increase its prices. Before deciding, I need to consider how price-sensitive its customers are. I'm going to look for evidence about competition and brand loyalty because those factors could influence demand."

That narration reveals the decision-making process behind the finished answer.

In Mathematics, a teacher might explain why they choose a particular method rather than simply demonstrating the calculation.

In History, a teacher might verbalise how they assess the reliability and usefulness of a source.

In Product Design, a teacher could explain the considerations behind selecting one material over another.

These explanations expose the thinking that experts often perform automatically.

Three strategies for overcoming expert blind spots

1. Conduct an assumption audit

Before teaching a challenging concept, examine the knowledge pupils will need to access it.

Consider a lesson on virtual memory.

Do pupils securely understand RAM, secondary storage and why memory capacity matters?

If those foundations are insecure, an otherwise excellent explanation may be inaccessible.

Identify the assumptions underpinning your lesson and check whether they're justified.

2. Narrate the decisions, not just the steps

When modelling a task, explain why you're making particular choices.

Instead of saying, "Now we calculate the percentage change," explain why percentage change is the appropriate measure.

This helps pupils develop the judgement needed to approach unfamiliar problems independently.

3. Use pupil explanations diagnostically

Ask pupils to explain how they reached an answer.

Their explanations can reveal missing knowledge that a correct final response might conceal.

A pupil who can reproduce a method may not understand why it works.

Equally, an incorrect answer may reveal a specific misunderstanding rather than a complete absence of knowledge.

Listening carefully allows us to respond more precisely.

What does this mean for professional development?

For ECTs: When pupils struggle, resist the temptation to assume that your explanation simply needs repeating. Instead, identify which knowledge or connection might be missing. Ask pupils to describe the point at which they became uncertain. Their responses can provide valuable information for adapting your teaching.

For mentors: Avoid relying on statements such as "They should already know this." Help your ECT identify what successful performance actually requires. During lesson reviews, select one task and unpack the knowledge, vocabulary and decisions pupils needed to complete it. This makes your own expertise visible too.

For experienced teachers: Choose a familiar task and attempt to narrate every decision involved in completing it. You may be surprised by how much thinking you've automated. Consider recording a short explanation or asking a colleague to identify assumptions you've overlooked.

A moment for reflection

What feels completely obvious in your subject now that once had to be carefully explained to you?

Think back to when you first encountered that concept.

What helped you understand it?

What confused you?

Which explanation finally made everything click?

Those memories may offer valuable clues about how to support your pupils today.

Final thoughts

Expertise is one of our greatest professional assets.

It allows us to recognise patterns, anticipate complexity and develop increasingly sophisticated understanding of our subjects.

But expertise can also distance us from the experience of learning something for the first time.

Effective teaching requires us to bridge that distance.

Sometimes, the most powerful thing we can do is slow down, make our thinking visible and remember that what feels obvious to us may represent an important new discovery for somebody else.

Expertise helps us see further. Great teaching sometimes requires us to look backwards.