You are speaking from my heart with your gut wrenching examples. I work in usability for quite some time now and we even offer a wireframing and usability testing tool to held designers avoid that kind of stuff. But I never understand, that even so called “usability professionals” test the workflows and processes of their sites many times, but very often leave the error messages to the programmers.

But it’s excatly when something goes wrong, that the user needs help from the system – he didn’s do the mistake on purpose!

Cheers,

Michael

I hate this one most, because credit card information usually contains large numbers…

Medical doctors are trained to follow the principle ‘first, do no harm’ (from the latin ‘primum non nocere’):
http://en.wikipedia.org/wiki/Primum_non_nocere

The basic idea is: while improving the patient’s health is an important objective, not making the patient’s health worse is even more important.

While product redesigns are always started with the best intentions of making the product better, changes to existing functionality can often have negative side effects for users.

Sometimes, existing functionality is removed by accident without realizing it. Sometimes, the changes are made deliberately because the team thinks they know better, only to be set straight by the complaints of angry users. Sometimes, unexpected technical complexities and/or schedule pressures force a team to make a decision they know is suboptimal.

The costs of a redesign mistake goes up the more users you have. There have been several recent examples of popular products angering users with a redesign. Next time you see that happen, ask yourself whether or not the company was applying the concept of ‘first, do no harm’.

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Good example! I appended it to the list above!