Measurement creates a pointer

But measurement can cut both ways. In track and field, we happen to measure speed, and so we cultivate agnation of speedsters. If we happened to measure running style, we would cultivate a nation of gazelles. The minute we choose to measure something, we are essentially choosing to aspire to it. A metric, in other words, creates a pointer in a particular direction. And once the pointer is created, it is only a matter of time before competitors herd in the direction of that pointer.

Youngme Moon talking about the the perils of measurement in Difference (p. 29).

I've often heard it said, "you are what you measure," but I like Moon's "you become what you measure" more.

In my day job, we do a lot of setting goals and measuring outcomes. We work very hard to define those goals, and only decide what we want to measure after we know what we're trying to achieve. By doing this, we hope to make sure we're measuring the right thing.

Another reason I'm interested in the question of measurement is that I've recently place my son in the education system. I've been reading a lot that indicates that standardized tests are having unintended consequences: encouraging teachers to teach the test or even to cheat. While I'm convinced we need educational testing and that the current culture is often a positive one, I'm still not convinced that standardized tests are measuring the right thing.