How to get your point across with spaced repetition

communication strategies

You’re writing a book. Or a technical manual. Or an advertisement. Whatever you’re writing, you have a key point you want the reader to come away with. “The revolution of October 1917 was inevitable.” “The central algorithm in the system is RSA.” “Zonko is better than Zarko.” Whatever your point is, to teach your reader of it, you should repeat that point throughout!

The reader leaves your writing with very little retained. You must make sure that your key point is one of those retained items. But there are many ways to emphasize your key point:

I want to emphasize the last method: say it repeatedly! If, like me, you’re an engineer, you have a bias against repetition. You think that concision is a virtue. You think that repetition is redundancy, to be squeezed out. Well, it’s not. Repetition serves a purpose. Repetition is your most powerful tool, because all that matters is what the reader remembers when they leave, and repetition is the most powerful way to remember.

Why do you remember your name and birthdate? Not because you were told them at birth, but because you’ve had to recall them thousands of times. Why do you remember the flags for curl? Not because you read the man page, but because you repeatedly consulted that man page every time you used it. Why do you remember the lyrics of Tubthumping? Not because Chumbawumba shouted the chorus at you (although they did), but because they repeated that infernal chorus twenty-seven times every time the song was played.

The state-of-the-art technique for memorization is spaced repetition, used by tools like Memrise, Duolingo, and Anki. One key word there is repetition, but the other key word is spaced. You did not have to write your name thousands of times on a chalkboard one day in childhood; instead, you have had to recall your name most days when talking to people and filling out forms. You did not lock yourself in a room with the man page for curl, repeatedly reading it until it was committed to memory; instead, you consulted it each time you used curl. The lyrics of Tubthumping are burned into your mind not just because they are repeated throughout the song, but also because the song was on the radio all through 1997.

To get your point across, it’s not enough to just repeat it. That repetition must be appropriately spaced. How do we space out our writing? Above, I illustrated a few communication strategies. At the top, we have the “Man page” approach: terse, concise, no repetition. This is the approach that many engineers want to take when explaining something. It’s too terse for most people, and does not result in good recall after reading. A naïve expansion of this approach results in the second diagram: the writing proceeds logically from beginning to end. In the naïve approach, there’s more time for the reader to ruminate, but such rumination is not aided by the writer. The ends of the writing, at the start and end, trail off, loose and frayed. This is why schools teach the “shit sandwich” approach: stick a summary at the start and the end (calling them an “introduction” and “conclusion”). There is at least some repetition and recall in the shit sandwich, but the reader still has to wade through a lot of shit to get there.

I think “good” writing uses some kind of fractal approach to repetition. The overall structure is that of the naïve approach, but with many opportunities for recall, at many levels of detail. Each repetition is colored by the general position in the text: what the reader has already read, what they trust they’ll soon read, and how it relates to the overall structure. By the end, the reader is acquainted with your overall argument, because she has read it many times and considered it from different angles.

Repetition is recall!