One stop testing Metrics

"Metrics are a system of parameters or ways of quantitative and periodic assessment of a process that is to be measured, along with the procedures to carry out such measurement and the procedures for the interpretation of the assessment in the light of previous or comparable assessments. Metrics are usually specialized by the subject area, in which case they are valid only within a certain domain and cannot be directly benchmarked or interpreted outside it."

Metrics are measurements. It is as simple as that. We use them all the time in our everyday lives. Entangling them in wordy definitions is just intended to make them seem more mysterious and technical than they really are.

So what sorts of things do we measure in our daily lives and how do we use them? Shopping for food is a good place to start. At the meat counter, there is a choice of cuts of different kinds of meat, all at different prices. If we just look at the total price, we may be misled. A nice round steak might cost $10.00 while a round roast might cost $8.00 even though it weighs the same as the steak. So to get the best value for our money we tend to look at the price per unit weight. This is a microcosm of the field of metrics.

There are two basis types of metrics. The first type is the elemental or basic measurement such as weight, length, time, volume, and in this example, cost. The second type is derived, normally from the elemental measurements. At the meat counter, the derived metric is dollars/weight (VIZ. $7.49/kg). This is called a normalized metric.

Generally speaking, normalized metrics are the most useful because they allow us to make comparisons between things that are different. Some other examples are miles/gallon, dollars/gallon, dollars/share, dollars/hr, and dollars/square foot to give but a few.

We also see metrics in sports. In hockey its shots on goal and plus/minus ratio. In baseball its batting average and errors per game. All of these numbers are provided in newspapers and sports magazines and if they disappeared there would be a great uproar among fans.

�When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of the meager and unsatisfactory kind.� - Lord Kelvin

Now Lord Kelvin wasn't right about everything he spoke about. He predicted that heavier than air flight was impossible. But about metrics, he was dead right.

We as shoppers apply this principle whenever we go to the market. If a cut of meat is marked $10.00 but has no weight assigned, we are likely to look for something else. The same would apply if the weight were given but no price. This is just plain old ordinary common sense. Yet we may go though our professional lives without using metrics to guide us in our work. Maintaining a "meager and unsatisfactory" knowledge about the way you earn your living is probably not the best approach.