[Experts can distinguish specific features beyond basic categories: instead of cat versus dog, the specific species; instead of red wine versus white, the dryness or type of grapes used.]

[Experts develop their precision by comparing many examples over years. Presenting contrasting cases shortens the time to learn by using carefully juxtaposed examples.]

[Learning what something is also means learning what it is not.]

[Decide which features are important to notice and pick contrasts for each of them.]

[Noticing differences is easier when similarities dominate.]