The most common validation error is neglecting to specify an alt attribute for img elements

I'M YELLING BECAUSE THIS SHIT IS IMPORTANT.

too awesome

If you test your own design, however, you might be less willing to admit its deficiencies. Designers can be too willing to dismiss user complaints or problems as minor or unrepresentative, when in fact the test indicates the need for a deep redesign.

Quite a hype - "Instead to make a single request it's possible to make multiple concurrent requests using the clients number option. Wbox will spawn the required number of processes, and every process will perform a query every second."

But, when they were asked to use the digital device, so-called "feature fatigue" set in. They became frustrated with the plethora of options they had created, and ended up happier with a simpler product.

Several decades' experience with quality assurance says that the best results come from following a systematic quality process, including reality checks every step of the way, rather than simply hoping that you got it right. - Grandpa Jacob owns them all.