The Tyranny of Metrics

He also warns against the use of all “input metrics,” that is, metrics that count what the army and its allies are doing, for these may be quite distinct from the outcomes of those actions: Input metrics are indicators based on our own level of effort, as distinct from the effects of our efforts. For example, input metrics include numbers of enemy killed, numbers of friendly forces trained, numbers of schools or clinics built, miles of road completed, and so on. These indicators tell us what we are doing but not the effect we are having. To understand that effect, we need to look at output metrics (how many friendly forces are still serving three months after training, for example, or how many schools or clinics are still standing and in use after a year) or, better still, at outcome metrics. Outcome metrics track the actual and perceived effect of our actions on the population’s safety, security, and well-being.