[bumby]

>Some things are reliably measurable; for those things be data-driven. Other things not so much, then use your expertise.

Maybe too much of a nit-pick, but how does one build expertise without data? I'll grant that it may be informally or subconsciously collected but it's still data.

It makes me think of Malcolm Gladwell's book Blink. There are lots of experts who can subconsciously chunk data to make intuitive and reliable decisions. But they got to that point often gathering lots of data in the form of experience.