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Error rate 0:52
A 52-second explainer of Error rate, narrated over the same demo you can try yourself.
Try the interactive Error rate demo
What this video covers
Error rate is how often people make errors while doing a task - mistakes per attempt, or the share of attempts that go wrong. It's a usability metric, not a verdict on users: a high error rate almost always points at a confusing design, not careless people, and the type of error tells you what kind of fix it needs.
When one in three attempts goes wrong, the instinct is "users aren't paying attention" - but if a third of people trip on the same step, the step tripped them. Error rate turns that into a number you can't argue with, and the type of error - a fumbled tap versus a misunderstood label - points straight at whether you've got an interface problem or a comprehension one.
