Today I had to explain to a group of non-technical people why is it important to run at least some user tests on your product. This is the anecdote I used, and since they liked it and it seemed to convince them, I thought I would share it here, just in case someone needs to explain the same thing.

This is a real story, and happened quite a long ago when they were inventing the dialog box (that is, the “Yes/No” dialog we often see on any computer) at Palo Alto Research Center.

When the software required confirmation from the user, it displayed a small window called a “dialog box”, that contained a question, and presented two buttons, for positive or negative confirmation. The buttons were labeled “Do It” and “Cancel”. The designers observed that a few users seemed to stumble at the point that the dialog was displayed, clicking “Cancel” when they should have clicked “Do It”, but it wasn’t clear what they were having trouble with.
Finally, the team noticed one user that was particularly flummoxed by the dialog box, who even seemed to be getting a bit angry. The moderator interrupted the test and asked him what the problem was. He replied, “I’m not a dolt, why is the software calling me a dolt?”

It turns out he wasn’t noticing the space between the ‘o’ and the ‘I’ in ‘Do It’; in the sans-serif system font we were using, a capital ‘I’ looked very much like a lower case ‘l’, so he was reading ‘Do It’ as ‘Dolt’ and was therefore kind of offended.

After a bit of consideration, we switched the positive confirmation button label to ‘OK’ (which was initially avoided, because we thought it was too colloquial), and from that point on people seemed to have fewer problems.

For non-english speakers (like myself), “dolt” means “idiot”, so the users were confronted with choosing between “Idiot” or “Cancel”. No wonder why they were annoyed!

Here you have the source, if you want to know more.