Working memory holds a handful of things so the list must hold the rest
💎CORE ARGUMENT
A head holds a handful of things at once. I do not mean that as a weakness to be trained away. It is closer to the width of a doorway, and anything built for a person has to fit through it.
Two consequences follow, and they pull in opposite directions.
The first is that the list must hold everything the head cannot. If a commitment lives only in my memory it is competing for one of very few slots, and it will push out the thing I am actually trying to think about. Writing it down is not tidiness. It is the only way to get the slot back.
The second is the one I missed for a year at work: a list that holds everything is a store, and a store is not a view. On a dispatch floor in Rotterdam in February, each dispatcher had 214 open exceptions before nine. We had built that list and were proud of its completeness. Nobody could use it, because nobody can look at 214 of anything. They told us what they wanted instead: five things, at 07:00.
So the design rule has two halves. Keep the full list, because memory cannot. Then show a person only as many items as fit through the door, and choose them well.
My own version is a card with one line on it, written at shutdown. The task list has dozens of entries. The card has tomorrow's first.
It breaks down when the few are badly chosen. A short list hides whatever the ranking got wrong, and the ranking is the hard part. It leans on 💎 A backlog is a stock and only the outflow shrinks it: trimming the view does not drain the stock behind it.
🧱BUILT FROM
🌍WHY IT MATTERS
I now ask two separate questions of any list: does it hold everything, and what does a person see first. They have different answers and usually different owners. A long list was never the failure. Showing it whole was.
Still open.
- Is five the right number for the digest, or only the number the dispatchers said first?
- What is the list equivalent of a chunk: a group by cause, by carrier, by lane?
- Does a card with one line on it work because of the limit, or because I wrote it by hand?
☑️NEXT STEPS
- Write the one-page case for the digest for the Q1 2026 list
- Ask Stellan how he reads a long exception list on a bad morning
📖 Miller on the limits of working memory: the limit is real, small, and stretched only by recoding items into larger chunks. Miller is careful about the exact number and so should I be.
💎 A backlog is a stock and only the outflow shrinks it: the 214 are a stock, and showing five does not shrink it. 💎 Notes should be written for the person who has forgotten everything: both notes start from the fact that my memory is not a place to keep things.
Working memory is a fixed, small hold. Anything not written down occupies part of it, so the list exists to free the hold. But a person reading a list is using the same small hold, so the list has to be shown a handful at a time or grouped into chunks.
The counter-case is the expert. A dispatcher of twenty years reads a long list as a few patterns, not as 214 rows, and a digest of five may take away the scan that made them good.
At work, 🔍 Exceptions digest by e-mail. At home, one line on a card: 🔹 Plan tomorrow's first task.