The inevitable weakness of metrics

MIT Technology Review 

Quantifying our lives is easier than it's ever been. But a philosopher of games warns that external metrics and data can never capture what's truly important. There are plenty of useful things a metric can reveal. There are even more it can obscure or corrupt. It took me well over a decade of tracking my own life in ever greater detail to fully appreciate this duality, which probably reveals something about both me and the nature of measurement. Like a lot of people bitten by the self-quantifying bug, I initially started gathering personal data to pursue a nebulous collection of goals and desires.