Jeff Sauro • September 17, 2004
The Power of Z
A common statistical way of standardizing data on one scale so a comparison can take place is using a z-score. The z-score is like a common yard stick for all types of data. Each z-score corresponds to a point in a normal distribution and as such is sometimes called a normal deviate since a z-score will describe how much a point deviates from a mean or specification point.Why use a Process Sigma?
The process sigma is helpful in three ways:Getting Started Finding the Right Sample Size
The Essentials of a Contextual Inquiry
A Brief History of the Magic Number 5 in Usability Testing
The Five Most Influential Papers in Usability
5 Examples of Quantifying Qualitative Data
Does better usability increase customer loyalty?
10 Things to Know about Usability Problems
Should you use 5 or 7 point scales?
How common are usability problems?
Why you only need to test with five users (explained)
Nine misconceptions about statistics and usability
What five users can tell you that 5000 cannot
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
Customer Analytics for Dummies A guidebook for measuring the customer experience Buy on Amazon | |
Quantifying the User Experience: Practical Statistics for User Research The most comprehensive statistical resource for UX Professionals Buy on Amazon | |
Excel & R Companion to Quantifying the User Experience Detailed Steps to Solve over 100 Examples and Exercises in the Excel Calculator and R Buy on Amazon | Download | |
A Practical Guide to the System Usability Scale Background, Benchmarks & Best Practices for the most popular usability questionnaire Buy on Amazon | Download | |
A Practical Guide to Measuring Usability 72 Answers to the Most Common Questions about Quantifying the Usability of Websites and Software Buy on Amazon | Download |