100 Things: Every Designer Needs to Know About People

88. People Make Predictable Types of Errors

In addition to thinking about the consequences of errors, as in the van der Linden study described previously, there is another useful error taxonomy. The Morrell (2000) taxonomy classifies two types of errors: performance and motor-control.

Performance Errors

Performance errors are mistakes you make while you’re going through the steps to complete a procedure. Morrell further divides performance errors into commission errors, omission errors, or wrong-action errors.

Commission errors

Let’s say you’re trying to get a task done, such as turning on the Wi-Fi on your tablet. All you have to do is touch the On/Off control on the screen, but you think that you also need to touch the drop-down menu and select ...