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In this edition of ⚗️DistillED, we're looking at non-examples — the deliberate contrast cases that sharpen where a concept ends and something else begins.
In this edition
📊 Do Now: Quick Poll!
When you introduce a new concept, how often do you deliberately show students what it is NOT?
What are Non-Examples?
A non-example is a deliberately chosen contrast case — an instance that almost fits a concept but doesn't, because it's missing the critical defining feature. The aim of a non-example is to draw a sharp boundary around what a concept actually is. You show what something isn't, precisely so students can see more clearly what it is.
In typical ⚗️DistillED fashion, here's what Non-Examples are — and what they aren't:
👎 Non-Examples ARE NOT:
Random Wrong Answers → Choosing an unrelated contrast case teaches nothing (a circle is technically a non-example of a triangle, but it's too obviously different to be useful)
Trick Questions → The point is clarity, not confusion
Optional Extras → Presenting examples only is the default for most teachers; it leaves concept boundaries dangerously fuzzy
The Same as Misconceptions → Non-examples are proactive (you choose them in planning); misconceptions are reactive (what students already believe)
👍 Non-Examples ARE:
Deliberate → Chosen in advance, not improvised under pressure
Closely Related to the Concept → Sharing surface features with the example, differing only in the critical feature
Paired with Examples → Always shown alongside what the concept is, not in isolation
Cross-Subject → Applicable wherever concepts need to be taught: science, maths, English, humanities, and beyond
It's worth noting that the IS / IS NOT format used in every ⚗️DistillED post is itself a non-example structure — examples of what the concept is, set directly against cases of what it isn't. Carl Hendrick captures the essential logic:
“Learning is driven by clear distinctions — knowing what something is requires knowing what it isn't.”
The only question is whether you're applying that same logic deliberately in your teaching, with the contrast cases chosen in advance rather than reached for in the moment.
Why Do Non-Examples Matter?
Let's start with boundary conditions. Here’s a scenario…
An English teacher introduces pathetic fallacy in a Year 8 unit on Gothic fiction. The examples are well chosen — a storm breaks as the protagonist discovers the body, fog descends as the detective loses the trail, rain hammers the windows during the argument. Students get it. Weather mirrors emotion. The teacher moves on.
In their essays, students begin identifying every weather reference in every text as pathetic fallacy. Rain at the start of a journey. Sunshine on a market day. A character noticing clouds because she's outside. One student argues that a weather forecast on a character's phone is pathetic fallacy because it predicts a storm.
What they had learned was: weather description in a literary text. The critical feature — that the weather must be used deliberately to reflect or amplify a character's emotional state or the atmosphere of a scene — had never been tested against a non-example. Without it, students applied the label to everything.
Example | Non-Example | |
|---|---|---|
Extract | "The storm tore through the village as Sarah read the letter, thunder cracking overhead like a verdict." | "It had been raining since Tuesday. Sarah pulled her coat tighter and walked to the post office." |
Is this pathetic fallacy? | ✅ Yes | ❌ No |
Why | The storm mirrors Sarah's emotional state. The thunder is framed as a judgment — the weather is doing interpretive work, not descriptive work. | The rain establishes setting and conditions. It has no connection to Sarah's inner state. It could be removed without changing the emotional meaning of the scene. |
Critical feature present? | The weather is used deliberately to reflect or amplify a character's emotional state | The weather is present, but it is not connected to emotion — it is incidental detail |
The diagram below makes the principle explicit. Examples sit inside the concept boundary — they all share the critical feature. Non-examples sit outside it. But not all non-examples are equal. The closer a non-example sits to the boundary, the more precisely it defines where the concept ends. A far-miss non-example ("she felt sad") is so obviously wrong it tells students nothing they didn't already know. A near-miss ("it rained all day") sits right at the edge — and that's exactly where the learning happens.
Anita Archer and Charles Hughes, in their excellent book Explicit Instruction: Effective and Efficient Teaching (2011), list providing examples and non-examples as the ninth of sixteen core elements of effective explicit instruction. Their definition is direct:
“In order to establish the boundaries of when and when not to apply a skill, strategy, concept, or rule, provide a wide range of examples and non-examples.”
Essentially, Examples prevent underuse — students applying a concept too narrowly. Non-examples prevent misuse — students applying a concept where it doesn't belong. Both are necessary. One without the other leaves the concept boundary open on one side.
This connects directly to how knowledge is stored. Knowledge is organised in long-term memory as mental models — schema. When students encounter a new concept through examples alone, the schema they build is often either too narrow (they think the concept only applies in the situations they saw) or too broad (they include things that shouldn't be there). Non-examples create the contrast that makes the schema accurate. They define the edges, not just the centre.
The faulty understanding point matters lots. A misconception formed in Year 7 doesn't sit quietly — it actively interferes with everything built on top of it. Non-examples are not just a teaching technique. They're a form of quality control on schema formation in long-term memory.
What’s more, Non-examples don't exist in isolation. They sit inside the wider discipline of explicit instruction — the structured, deliberate approach to introducing new content that Barak Rosenshine spent his career evidencing. When the presentation of a concept is designed carefully, with examples sequenced against contrast cases, students build accurate understanding the first time. When it isn't, teachers find themselves reteaching the same concept weeks later, correcting boundaries that were never drawn clearly in the first place.
Non-examples don't add complexity to a lesson. They remove the ambiguity that causes problems later.
How do I use Non-Examples?
The good news is that implementation doesn't require new resources or a redesigned lesson. It requires deliberate planning — specifically, choosing your non-examples before you walk into the room, not improvising them once you're there.
Educator Craig Barton puts it directly:
"I am a huge believer that in order to really understand something we must know both what it is and what it is not, hence I love a non-example."
From that belief, he points to two ideas that shape how non-examples work in practice:
Boundaries: Include boundary examples — cases right at the edge of the concept, where students have to genuinely think about whether it qualifies.
Variation: Make consecutive examples related — changing only one thing at a time so students can identify the critical feature.
Engelmann and Carnine (1982) add a third requirement that underpins both: the non-example must differ from the example in only the critical defining feature. Everything else stays the same. If your non-example looks completely different from your example, students cannot work out what made the difference. The contrast needs to be close — and that closeness needs to be planned, not improvised.
Here is how to put this into practice:
Step | Explanation | Example |
|---|---|---|
Step 1: Identify the Critical Feature
| Before choosing any examples or non-examples, name the single feature that determines whether something belongs to the concept or not. This is what every contrast case must hinge on. If you can't name it clearly yourself, your students won't be able to either. | A teacher planning a lesson on metaphors identifies the critical feature: a direct comparison between two unlike things, stated as fact, without using 'like' or 'as'. Every example and non-example is then chosen to test that feature specifically. |
Step 2: Choose Non-Examples That Share Surface Features
| Your non-example should look almost identical to your example — same context, same surface appearance — but missing the critical feature. If too many things change at once, students can't identify what caused the difference. The contrast must be tight. | Teaching condensation: pair steam on a mirror (example) with raindrops on a window (non-example). Both involve water on glass. The difference — one involves a gas becoming a liquid, the other doesn't — becomes visible precisely because everything else is the same. "Look at these two. What's actually happening to the water in each case?" |
Step 3: Sequence Examples and Non-Examples Consecutively
| Show an example, then immediately show a related non-example. Pause. Ask students to identify what changed. Then show another example. The consecutive pairing is what makes the critical feature salient — students are comparing in real time, not from memory. | "This is a metaphor: 'The classroom was a zoo.' Now look at this: 'The classroom was like a zoo.' Is this still a metaphor? What changed? Take thirty seconds and write your answer on your whiteboard before I tell you." |
Step 4: Include Boundary Examples
| Once students have the basic idea, move to the boundary — cases that are just barely an example, or just barely not. These reveal whether a student genuinely understands the concept or simply recognises the obvious cases. Boundary examples are where real conceptual understanding gets tested. | "Here's a harder one: 'She has a heart of gold.' Is that a metaphor? What about 'Time flies'? These are edge cases — discuss with your partner. You need to use the critical feature to decide." |
Step 5: Use the Pause-and-Reflect Routine
| After showing each example or non-example, pause before revealing whether it fits the concept. Prompt: What's changed? What's stayed the same? With practice, this routine becomes automatic. Students apply it without being asked. The pause is not dead time — it's where the cognitive work happens. | "Before I tell you — ten seconds. Look at this and the one before it. One thing changed. What was it? Turn and talk to your partner… Go." Show the reveal only after students have committed to an answer. |
One final thought worth naming. When non-examples are chosen poorly — when they're too obviously different from the example, too random, or too distant — the activity teaches nothing. The non-example has to be close. It has to share enough surface features that students genuinely have to think about what makes it wrong.
That closeness is what creates the cognitive work. And it's the cognitive work that builds the schema.
Until next week!
— Jamie
If you want more:
👉 Read Explaining With Precision — designing explanations that reduce cognitive load and build clarity from the start
👉 Read Worked Examples — showing students how to complete a task, not just what the finished product looks like
👉 Read Activating Prior Knowledge — how schema activation shapes what students can learn next
👉 Get the DistillED Playbooks for practical, evidence-informed classroom practices
📥 Free One-Page Guide
Non-Examples One-Page Guide
This edition comes with a free one-page guide on Non-Examples — a practical summary of what they are, why they matter, and how to use them in your classroom. Print it, share it with your department, or use it as a planning reference before your next lesson.
⚗️DistillED+ Exclusive Content
This week, ⚗️DistillED+ members get access to the Non-Examples CPD PowerPoint and Strategy Checklist — breaking down how to identify critical features, design deliberate contrast cases, and build non-examples into your planning so that concept boundaries are clear from the first time you teach them.
