Question 340:Hi Jeff,
You have lots of great info on your site; thanks! However, I'm trying to reconcile some different items and they seem to disagree. Can you tell me if I'm misunderstanding something? In this article you use the ex, "Here’s why. If five out of five users complete a task, you can be 95% confident that the completion rate could be as high as 100% but it also could be as low as 48%. In other words, if you tested another five users, their completion rate will fall somewhere between 48% and 100%. Or if you're testing 100 users, as many as 52 of the 100 could fail the task." But when I put those #s (5 of 5) into your "Confidence Interval Calculator for a Completion Rate", none of the confidence intervals it generates are as low as the 48% mentioned in the example from your article.