Make Something That Teaches

Notes you write for yourself are fragments and arrows with steps missing, because you knew those steps at the time. They make perfect sense today and are close to useless in six weeks. Notes written for a reader look different: complete sentences, every step shown, a worked example, a warning about the common mistake. Making that shift is the whole idea of this lesson. Writing for a reader forces you to fill in the gaps you'd otherwise skip, because you cannot leave out a step for a stranger — and finding the missing step is exactly where the learning happens. A teaching artifact is anything you make that could teach someone else: notes, a diagram, a cheat sheet, a worked example, a short lesson.

Drawing a diagram from memory is one of the hardest and most useful things you can do, because of what it forces. You must decide what the parts are — copying skips that decision entirely. You must decide how they relate, and arrows force you to commit to direction, order and cause. You must label every connection, because an unlabelled arrow is where 'I sort of know they're related' hides. And you must lay it out spatially: what's central, what's a branch, what comes first. Draw it closed-book, then compare with the real one. Whatever is missing, misplaced or unlabelled in yours is your gap list.

A one-page cheat sheet is powerful because of its limit, not despite it. You cannot fit everything on one page, so you have to decide what matters — and that decision is the study. The rule for what to keep: the things you keep forgetting, and the things everything else depends on. Definitions you can already recite don't earn a place. Then comes the step most students never take: cover the sheet and reproduce it from memory on a blank page. If you can rebuild your own cheat sheet without looking, you barely need it — and that's the state you want to walk into the exam in.

A five-minute mini-lesson has five moves. The HOOK: why should anyone care about this — thirty seconds. The CORE IDEA: the whole thing in one sentence, thirty seconds. HOW IT WORKS: the steps or the mechanism in order, about two minutes. An EXAMPLE: one worked case start to finish, a minute and a half. And WATCH OUT: the mistake people make here, thirty seconds. Deliver it out loud, standing up, without notes — to a friend, a sibling, or an empty room if that's what's available. Standing and speaking changes what your brain does; it's harder to skim past a gap when you can hear yourself go quiet.

Keep everything you make. One folder per subject: explanations, diagrams, cheat sheets, worked examples, mini-lesson plans, and your error log. Date it all. By exam time you're holding a revision course you wrote yourself, in your own words, aimed exactly at your own gaps — and no purchased study guide can match that fit, because none of them knows which four things you keep getting wrong. Don't throw old drafts away either. Reading a draft from six weeks ago and seeing how clumsy it looks is direct evidence that your understanding has moved, which is the kind of feedback that's otherwise very hard to get.