A non-example is something that does not fit the definition of a concept or category. It helps to illustrate what something is not by showing contrasting examples.

Here are some examples:

* Concept: A mammal

* Example: Dog

* Non-example: Fish, bird, snake

* Concept: Fruit

* Example: Apple

* Non-example: Tomato (botanically a fruit, but culinarily a vegetable), potato

* Concept: Even number

* Example: 2, 4, 6, 8

* Non-example: 1, 3, 5, 7

Why use non-examples?

* Clarify understanding: Non-examples help distinguish between what is included and excluded from a concept.

* Improve learning: By seeing what something is *not*, it helps students solidify their understanding of what it *is*.

* Problem-solving: In problem-solving, non-examples can help identify potential pitfalls or incorrect approaches.

In short, non-examples are like negative spaces in art – they define what something is by highlighting what it is not.