From Chapter3: What Would The User Do in 97 Things Every Programmer Should Know
WE ALL TEND TO ASSUME THAT OTHER PEOPLE THINK LIKE US. But they don’t. Psychologists call this the false consensus bias. When people think or act differently from us, we’re quite likely to label them (subconsciously) as defective in some way.
This bias explains why programmers have such a hard time putting themselves in the users’ position. Users don’t think like programmers. For a start, they spend much less time using computers. They neither know nor care how a computer works. This means they can’t draw on any of the battery of problem-solving techniques so familiar to programmers. They don’t recognize the patterns and cues programmers use to work with, through, and around an interface.
The best way to find out how a user thinks is to watch one. Ask a user to complete a task using a similar piece of software to what you’re developing. Make sure the task is a real one: “Add up a column of numbers” is OK; “Calculate your expenses for the last month” is better. Avoid tasks that are too specific, such as “Can you select these spreadsheet cells and enter a SUM formula below?”—there’s a big clue in that question. Get the user to talk through his or her progress. Don’t interrupt. Don’t try to help. Keep asking yourself, “Why is he doing that?” and “Why is she not doing that?” more…
You can get a sense of what this book is about and also other similar efforts here.