What Do They Actually Need to Know?

2 hours ago

5 min read

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

“A curriculum isn’t everything we could teach. It’s the knowledge we deliberately choose to prioritise.”

The temptation to teach everything

One of the greatest joys of teaching a subject you genuinely love is having so much knowledge to share.

You know the fascinating examples, the unusual applications, the historical background and the little details that bring a topic to life.

And, occasionally, you find yourself halfway through an enthusiastic explanation before realising you've wandered considerably further than the lesson originally intended!

I suspect most experienced teachers recognise this.

Subject expertise is enormously valuable. It allows us to answer unexpected questions, make meaningful connections and bring depth to our teaching.

But it also presents an interesting challenge.

Just because we know something doesn't automatically mean our pupils need to learn it right now.

Curriculum time is finite. Pupils' attention is finite. And the amount of new information they can meaningfully process at once is limited.

That makes curriculum prioritisation one of the most important decisions we make as teachers.

Curriculum thinking is about making choices

Section 3 of the April 2021 Early Career Framework emphasises the importance of identifying essential concepts, knowledge, skills and principles within a subject.

This reflects a fundamental distinction between knowing a subject and understanding its curriculum.

A subject represents a vast and evolving body of knowledge.

A curriculum is a deliberately selected and sequenced pathway through that knowledge.

Michael Young's work on powerful knowledge provides an interesting perspective here. Young (2008) argues for the importance of giving pupils access to specialised knowledge that takes them beyond their everyday experiences.

This doesn't mean filling lessons with increasingly sophisticated information.

It means identifying knowledge that helps pupils explain, question and understand the world in ways they couldn't previously.

The challenge is deciding which knowledge will make the greatest difference.

And those decisions require genuine subject expertise.

What makes knowledge essential?

When planning a topic, I find it useful to think about three different purposes that knowledge might serve.

Foundational knowledge provides the building blocks for understanding.

Connecting knowledge helps pupils recognise relationships between concepts.

Enabling knowledge allows pupils to access more sophisticated learning later.

Consider teaching computer memory.

Pupils need to understand the difference between primary and secondary storage, the purpose of RAM and ROM, and why computers require different forms of memory.

These concepts provide the foundations for later learning about virtual memory, operating systems and computer architecture.

I could introduce detailed historical developments in memory technology or explore highly specialised hardware implementations.

Those details might be fascinating.

But if pupils leave the lesson unable to explain why RAM is volatile, my priorities have probably become muddled.

The question isn't whether additional information has value.

It's whether that information deserves curriculum time at this particular point in the learning journey.

Why prioritisation matters for learning

Cognitive Load Theory, developed by John Sweller (1988), helps explain why carefully selecting information matters.

Working memory has limited capacity when processing unfamiliar material.

When pupils encounter too much new information simultaneously, they may struggle to identify relationships between important ideas.

This doesn't mean making learning artificially easy or avoiding complexity.

It means managing how complexity is introduced.

Barak Rosenshine's (2012) Principles of Instruction similarly emphasise presenting new material in small steps, checking understanding and providing opportunities for guided practice.

A well-designed curriculum supports these approaches by ensuring that essential knowledge is introduced, secured and revisited before pupils are expected to apply it in increasingly demanding contexts.

Prioritising knowledge isn't reducing ambition. It's creating the conditions for deeper understanding.

What does this look like across different subjects?

In Mathematics, understanding proportional relationships is more important than memorising a collection of disconnected calculation procedures. Secure proportional reasoning supports later learning in algebra, geometry and statistics.

In English, pupils studying a novel need sufficient contextual and vocabulary knowledge to interpret its meaning. However, an extensive historical detour may contribute little if it doesn't help pupils understand the text.

In Business, teaching market segmentation requires pupils to understand how businesses identify and target different customer groups. Numerous real-world examples can help, but pupils must ultimately be able to apply the underlying principle to unfamiliar businesses.

In Food Technology, understanding why temperature control matters for food safety is essential. Exploring every possible microorganism may be interesting, but it shouldn't overshadow the principles pupils need to apply safely.

Across subjects, the same question applies:

Which knowledge will pupils need to think successfully about what comes next?

A practical approach: the five essentials

Before beginning a new topic, try identifying five things you would want every pupil to remember six months later.

These might include a combination of concepts, vocabulary, principles and relationships.

Then consider:

Identify: Which five pieces of knowledge are genuinely indispensable?
Sequence: What must pupils understand before they can learn each one?
Explain: Which examples or representations will make the knowledge accessible?
Check: How will you establish whether pupils have understood it?
Revisit: Where will pupils encounter and apply this knowledge again?

This isn't intended to limit a topic to five facts.

Instead, it creates a useful planning discipline.

It encourages us to distinguish between what pupils must securely understand and what can enrich that understanding.

Importantly, enrichment still matters.

The fascinating examples and unexpected connections that make subjects enjoyable shouldn't disappear.

They simply need to serve a clear educational purpose.

Supporting professional development

For ECTs: Start with the curriculum rather than the activity. Identify the essential knowledge before deciding how pupils will encounter it. Ask experienced colleagues which concepts are foundational and which misconceptions are most likely to prevent future progress.

For mentors: Make your curriculum reasoning explicit. Rather than simply recommending resources, explain why particular knowledge deserves attention. Discuss what you deliberately leave out and how you decide when additional detail is helpful.

For experienced teachers: Revisit a favourite topic. Are there activities or examples that remain because you've always enjoyed teaching them? Consider whether they still support the intended learning. Sometimes refining a curriculum means being willing to remove something good to make space for something more important.

A moment for reflection

If pupils remembered only five things from the topic you're currently teaching, what would you want those five things to be?

Now look at your planned lessons.

Are those five things receiving the greatest attention, practice and opportunities for retrieval?

Or are they competing with information that is interesting but less essential?

Final thoughts

We cannot teach everything.

But we can make thoughtful decisions about what deserves our pupils' time and attention.

A strong curriculum isn't defined by how much information we manage to include.

It's defined by how carefully we select, sequence and revisit the knowledge that matters.

And sometimes, becoming a more effective teacher means learning not just what to teach, but what to leave for another day.