1.
Measuring Usability: Calculating a Sigma Level from Task Success
A sigma value is a description of how far a sample or point of data is away from its mean, expressed in standard deviations usually with the Greek letter σ ...
2.
Measuring Usability: Sample Size Calculator for a Completion Rate
Use this calculator to understand how sample size changes will affect the .... Determine a sample size with confidence level of 95% that will show the true ...
3.
Measuring Usability: Ask a Statistics Question
A test statistic is a value determined from sample information used to reject or not reject the null hypothesis. All hypothesis testing is based on ...
4.
Measuring Usability: Sample Size Calculator for a Completion Rate
Use this calculator to understand how sample size changes will affect the ... If 350 respondents out of a random sample of 1000 Americans reported that they ...
5.
Measuring Usability: Sample Size Calculator for a Completion Rate
Use this calculator to understand how sample size changes will affect the ..... out of a random sample 167 students pass an exam out of the 300. how do you ...
6.
Measuring Usability: Confidence Interval Calculator for a ...
Use this calculator to calculate a confidence interval and best point estimate for an .... Be sure to check out the online confidence interval tutorial. ...
7.
Measuring Usability: What's a Z-Score and Why Use it in Usability ...
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 ...
8.
Measuring Usability: Measuring & Analyzing Task Times
It's very important to know there are many complexities when deciding to measure task times. Upon initial consideration it may seem like a straightforward ...
9.
Measuring Usability: Calculating Sample Size for Task Times ...
With continuous data like task times, the sample size can be even smaller. The continuous calculation is a bit more complicated and involves somewhat of a ...
10.
Measuring Usability: Restoring Confidence in Usability Results
Adding confidence intervals to completion rates in usability tests will temper both excessive skepticism and overstated usability findings. ...
