Jeff Sauro • January 4, 2008
Use this calculator to understand how sample size changes will affect the confidence interval around a completion rate. For more context, see the Sample Size article.Known Users: Most Likely Completion Rates
Known Minimum Completion Rate: Unknown Users
Jeff Sauro is the founding principal of Measuring Usability LLC, a company providing statistics and usability consulting to
Fortune 1000 companies.
He is the author of over
15 journal articles and 4 books on statistics and the user-experience.
More about Jeff...
10 Metrics for Testing Website Navigation
Five Techniques for Moderating Usability Tests
Confidence Interval Calculator for a Completion Rate
8 Ways to Show Design Changes Improved the User Experience
How to Conduct a Usability test on a Mobile Device
What five users can tell you that 5000 cannot
97 Things to Know about Usability
Should you use 5 or 7 point scales?
Why you only need to test with five users (explained)
Nine misconceptions about statistics and usability
5 Examples of Quantifying Qualitative Data
Does better usability increase customer loyalty?
A Brief History of the Magic Number 5 in Usability Testing
The Five Most Influential Papers in Usability
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