Hi Nick,

thanks for sharing! Really nice to read. :) As someone who's done a fair amount of academic research on this topic, I have a couple of questions and one general comment, though:

- Why do you categorize DAU/MAU as attitudinal? That's purely behavioral and has nothing to do with what users say.

- "The great thing about SUS is that it requires a relatively small sample size." --> What is a relatively small sample size? And why should SUS not require a large one?

- Why don't you list a single instrument that *actually* measures UX? For instance, AttrakDiff, UEQ, or meCue?

General comment: Of all the metrics you mention, only time on task, error rate, and SUS strictly fit the definition of a UX metric. The rest might be influenced by UX, but are at best proxy indicators and not "UX metrics."

I've relatively recently published a piece on this whole topic myself. I don't wanna spam here, but would love to hear your thoughts.

https://uxdesign.cc/conversion-rate-average-order-value-are-not-ux-metrics-9d6e7e40e286

Best,

Max