An example might help illustrate the practical consequences of the ergodic switch. Imagine you want to reduce the number of errors you make when you are typing on a keyboard by changing the speed at which you type. The averagarian approach to this problem would be to evaluate the typing skills of many different people, then compare the average typing speed to the average number of errors. If you do this, you will find that faster typing speeds are associated with fewer errors, on average. This is where the ergodic switch comes in: an averagarian would conclude that if you wanted to reduce the number of errors in your typing, then you should type faster. In reality, people who type faster tend to be more proficient at typing in general, and therefore make fewer errors. But this is a “group level” conclusion. If you instead model the relationship between speed and errors at the level of the individual—for instance, by measuring how many errors you make when typing at different speeds—then you will find that typing faster actually leads to more errors. When you perform the ergodic switch—substituting knowledge about the group for knowledge about the individual—you get the exact wrong answer