Learn the Boundary, Not Just the Rule

A concept can feel clear in a familiar example and still be hard to use elsewhere. One useful practice is to learn its boundary as well as its definition.

Choose one idea you’re studying, then make three small examples:

• A case where the idea clearly applies.
• A near-miss where one important condition is different.
• A real task where you must decide whether it applies.

Write down your reasoning before checking your notes. A week later, revisit the real task: would you make the same call, and what evidence would change it?

This turns study into a test of understanding, not just recognition. If the boundary is still fuzzy, you’ve found a precise question for the next round of learning.