Research methods
Task success rate
Also calledSuccess rate, Completion rate
The percentage of participants who complete a task correctly. It is the most basic measure of whether a design works.
In a tree test, success means choosing the correct destination. In a usability test, it means finishing the task without help. Either way, it is reported per task, because a structure can work well for one task and badly for another.
Pair it with directness or time on task: a task most people eventually complete after wandering is still a problem.