Kenton Kivestu defines the difference between accuracy and precision, and then discusses what it means in the context of product decisions:
There is a significant opportunity cost in consistently prioritizing precision over accuracy. Accuracy is about launching what the market needs, precision is about optimizing and delivering relentlessly on it. Unless you’ve nailed the former, material effort on the latter is going to be wasted because you’re optimizing something too far from the true north (the accurate goal) you should be pursuing.
This is an important point. Any call for data-driven design (in the quantitative, 41 shades of blue sense of the word) needs to come with a disclaimer that it’s an extremely useful approach to get closer to the middle of a target (precision), but it’s useless if you’re shooting at the wrong thing (accuracy).
(link via @ixhd)