Metrics and measurement

As we write this, we find ourselves trying to navigate between two extremes. On the one side, we have the sort of naive optimism of irresponsible numbers. On the other, we have an open hostility to software metrics. As usual, the best option is a middle path.

For our purposes, a metric is a number with labels attached. The number three does not speak for itself, but if that were three programmers are working on that feature, then we have a metric. We speak in metrics all the time. For example, “We have 5 days until Friday, and we are planning on releasing Friday at 3 P.M.” lists two different metrics. Metrics as we use them are, according to the Oxford English Dictionary, just a system of measurement. We measure things all the time. So, we don’t want to reject metrics as a concept.

There is, however, a more subtle version of the word metric. This is the implication that is usually quoted: “If you can’t measure it (turn...