Column: Good Questions

What is a confidence interval? I wanted to know that recently and turned to one of my favorite books: Measuring the User Experience, by Tom Tullis and Bill Albert. And here’s what they say:

“Confidence intervals are extremely valuable for any usability professional. A confidence interval is a range that estimates the true population value for a statistic.”

Then they go on to explain how you calculate a confidence interval in Excel. Which is fine, but I have to admit that I wasn’t entirely sure that once I’d calculated it, I really knew what I’d done or what it meant. So I trawled through various statistics books to gain a better understanding of confidence intervals, and this column is the result. Read More

Here are my basic best practices for buttons:

1. Make buttons look like buttons.
2. Put buttons where users can find them.
3. Make the most important button look like it’s the most important one.
4. Put buttons in a sensible order.
5. Label buttons with what they do.
6. If users don’t want to do something, don’t have a button for it.
7. Make it harder to find destructive buttons.

Nothing particularly revolutionary there, right? Ever since the <button> tag arrived in HTML4, buttons haven’t been especially difficult to create. Despite this, it’s rather easy to find buttons that don’t comply with these basic best practices, so I’m going to dig into them a little deeper in this column. Read More

One of the nicest things about being an author is that, from time to time, people write to say they enjoyed our book, Forms that Work: Designing Web Forms for Usability. Of course, I write back and ask what they like about it. And surprisingly often, the reply is “question protocols.” Read More