A new study (pdf) questioned the cognitive benefits of highly detailed measurements. Jonah Lehrer warns that precise feedback can discourage us from getting closer to our goals:
The problem with precision … is that it can often be discouraging. Let’s say you want to lose 10 pounds. After following a strict diet for a few days, you then decide to weigh yourself. The good news is that you’ve lose weight. The bad news is that you’ve only lost 4 pounds. While that represents progress, it probably feels pretty disappointing, since you’ve already worked hard and you’re not even half way to the goal. As a result, you might become a little less motivated, which means that you start to cheat on your diet. Before long, those pounds are back – you’ve been undermined by the precise feedback.
The larger point is that the exactitude of the scale made it impossible to ignore the lack of success, which makes us more likely to surrender. And this is where vagueness comes in: when information is ambiguous we typically settle on more generous interpretations – Perhaps we’ve lost eight pounds! Perhaps we’re just retaining water! – which means that we stay motivated.
The Dish 