Why compression is the mechanism
Ordinary note-taking is additive: you write down what you hear, and the notes grow. Nothing in that process ever asks whether a fact deserves its space. A page limit does — and it asks about every fact, individually, forcing you to rank the entire module against itself.
Ranking requires understanding relationships. You cannot decide that three formulae can be replaced by one plus a rule unless you know they're related. You cannot cut an example unless you know what it exemplifies. The one-page constraint smuggles in the elaborative work that chunking describes, without you having to remember to do it.
What goes on it, and what never does
| Include | Exclude |
|---|---|
| Formulae you'd lose the question without | Formulae you've used forty times and could not forget |
| Decision rules: when you see X, do Y | Definitions you understand — they compress into a word |
| Constants, units, conversion factors | Worked examples — they eat a quarter page and teach nothing at a glance |
| The exceptions you keep getting wrong | The rules you never get wrong |
| Diagrams whose structure you can't reproduce | Anything you included because it was hard to learn rather than easy to forget |
That last exclusion is the discipline people find hardest. The instinct is to put the difficult material on the sheet. The correct criterion is *forgettability*, not difficulty: something you spent six hours understanding is now understood, and something arbitrary you learned in a minute is what will vanish under pressure.
How to build one
- 1
Start from past papers, not from your notes
Go through three past papers and list what you'd have needed to hand for each question. That list is your first draft and it's shaped by the exam rather than by the lecturer's coverage. Notes-first cheat sheets are always too even.
- 2
Write draft one with no space limit at all
Everything you might want. It'll be three or four pages. Don't fight it yet — premature compression makes you cut things you haven't evaluated.
- 3
Cut to one page by merging, not deleting
The good cuts are merges: five special cases become one general rule plus two exceptions. Every merge you find is a genuine piece of understanding, and it's the reason this step is the actual revision.
- 4
Rewrite it by hand, small, in one sitting
Handwriting forces you to process every character, and the spatial layout of a hand-made sheet is memorable in a way a typed one isn't. Many people can recall where on the page something sat even when they can't bring the page.
- 5
Test it: sit a past paper using only the sheet
This finds the omission you'd otherwise discover in the exam. Anything you had to look up elsewhere gets added; anything you never glanced at gets cut, freeing space.
- 6
Rebuild it from memory the day before
Blank page, reproduce the whole sheet. This is a complete module brain-dump disguised as an admin task, and it takes twenty minutes. For a closed-book exam, this step is the entire point of having made the sheet.
Layout decides whether you can use it under pressure
In an exam you have perhaps eight seconds to find something before the lookup costs more than it saves. A dense wall of tiny text fails this test no matter how complete it is.
- One topic per visual block, with clear whitespace between blocks. Whitespace is not wasted space; it's what makes retrieval possible.
- Same location every time. Constants always bottom-right. Decision rules always down the left. You're building spatial memory as well as a document.
- Colour by type, not by prettiness. One colour for formulae, one for exceptions, one for units. Two or three total.
- Boxes around the five things you'll actually need. If everything is emphasised, nothing is.
- Landscape orientation usually fits technical material better than portrait — wider lines suit equations.
Closed-book exams: build it anyway
For a closed-book exam, the cheat sheet becomes a memorisation target rather than a reference. One page is a realistic thing to commit to memory; a module's notes are not. Build it, then practise reproducing it from a blank page every day for the last week — three or four attempts is usually enough to get it near-perfect.
In the exam, reproduce it in the margin in the first two minutes, before you read the questions. It costs two minutes and converts a memory that's under load into a reference that isn't. This is a standard technique and it's legitimate in almost every exam — check your regulations rather than assuming.
Common mistakes
- Downloading someone else's. It's a fine reference and worthless as revision — the compression decisions were made by someone else, and those were the product.
- Making it too early. Build it after you've covered the material and done some past papers, so the exam shapes it. Week one produces an even, useless summary.
- Shrinking the font to fit more. If it's unreadable under stress it's not a cheat sheet, it's a comfort object.
- Never testing it. An untested sheet reliably omits something the exam asks for on the first page.
- Copying rather than compressing. If your sheet is your notes at 6pt, you've done transcription, not revision, and gained nothing.