Corrections
Every claim about the world we published and later found wrong, kept here permanently.
Why this page exists
A retraction is never silent
Our methodology carries a rule called “Mistakes are recorded and answered, in public”. It says that when a published claim turns out to be wrong, we write down what happened and correct it where you can see it. This is that page. It is linked from the footer of every page on this site, and it is not going to be moved somewhere quieter as it gets longer — including once it has more than one entry on it.
The argument against publishing this is real and we will state it rather than pretend it away: a list of our own mistakes is a permanent, searchable document, and someone will eventually read it looking for a reason not to hire us. The exposure runs the other way. The mistakes exist whether or not they are listed — in the page history, in the ledger, in the inbox of whoever relied on the number. Not listing them removes only the evidence that we caught them and fixed them.
Each entry says what we claimed, what was wrong with it, what we did about it, and whether it is still open. An entry stays open until there is a recorded change to a rule or to code that makes the same mistake harder — noticing is not the same as fixing, and we do not get to close our own entry by writing it down.
The record
What we got wrong
Newest first. Where a figure was withdrawn rather than replaced, the point it was making usually still holds — we make it now without a number attached, which is the honest version.
“42% of the knowledge a role depends on is held by one person only” — withdrawn 23 August 2026
What we claimed: that figure appeared on our knowledge page and in one article. What was wrong: its only support was a survey commissioned by a software vendor in 2018, and no sentence in it could be quoted to support the number. We spent a research pass looking for a stronger measurement and refused all three candidates we found. What we did: the figure came out of the copy on 23 August 2026. The source is still listed on the article with the withdrawal stated on the record. The point it illustrated — that critical knowledge concentrates in individuals — still holds, and we make it now without a figure attached. This entry is open: the retraction is still waiting on a signature, and the check that would have required one does not exist yet.
What is not here
The limits of this page, stated plainly
This page lists what we found. Nothing detects a mistake nobody noticed, and no process we could build would change that. If you think a number on this site is wrong, the fastest way to get it looked at is to tell us which page and which figure.
Typos, broken links and rewrites for clarity are not corrections and are not listed here. This page is for claims about the world that we published and that turned out not to hold.
Think one of our numbers is wrong?
Tell us the page and the figure. We would rather add an entry here than leave it standing.