Original measurement

Measured here, not quoted from elsewhere

Every lesson on this site reports what somebody else published, with the source named and its weakness stated where it has one. This is the part that does not: measurements run by Emad Sharaki, published with the method, the numbers, the limits and any corrections. Free to read and free to quote.

Each one exists because a question came up in client work that nobody had published an answer to, and the honest options were to guess or to measure. What gets published here is the measurement, including the parts that went wrong: one study's headline figure moved fourteen points after a correction, and that correction is on the page rather than in a footnote.

None of it is a benchmark you can look yourself up in. A study here measures one category in one period, states the method so you can run it on yours, and says where the numbers stop transferring.