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Make Products Easy to Use Correctly and Hard to Use Incorrectly
Good user interface designs help users avoid and recover from errors. Why don’t all products do that?
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I recently tried out some online life expectancy calculators to estimate my statistical expiration date. Many such calculators are simplistic, asking for just a few bits of data and then making a fuzzy guess. I found a more comprehensive calculator that requested no fewer than 35 pieces of information about my personal characteristics, family background, medical history, and lifestyle. The website provided drop-down lists so that I could select values for the many data items it requested. Nice.
However, the website did have one small user interface design problem, as this screenshot illustrates:
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After entering all of my data, I went to click on the Calculate button to see how much longer I might be around. However, I accidentally hit the Reset button instead. As the screenshot shows, those two buttons are styled identically. They aren’t easy to read because of a medium-gray-on-light-gray-against-even-lighter-gray-background color scheme. Also, they…