Working Up

by Dwayne Phillips

A reminder about models. Please take care when using them to predict the future.

George Box is credited with:

all models are wrong, but some are useful

It is a model, an approximation that helps describe real life. It is not real life. Some of these descriptions are useful to help us understand things. We need to remember, however, that every model is wrong.

Consider a watch with an analog face. A watch is a model of the time. If the watch is running, i.e., the hands are moving, it is NEVER correct. It is always off the standard time, even if it is off by only a few nanoseconds; it is off and incorrect.

Now consider the watch that is not running (dead battery, etc.). Its hands are stopped. It is exactly correct two times a day.

What would you rather have?

• A watch that is never correct, but is always fairly close.
• A watch that is correct twice a day, but most of the day is way off.

Let’s be careful in how and when we apply models to real life. Let’s especially be careful when we use models to predict the future.