Thank you Tamara! Sample size really depends on your margin of error or the confidence interval you are going for. In this article, Jeff gives a fantastic table for reference: https://measuringu.com/sample-size-recommendations/
I usually go for about 25-30 participants for a quant usability test because that gets around a 15% margin of error and that is typically what my stakeholders have felt comfortable with in the past! Hope that helps!
So I feel like number of errors falls into both categories -- it can slow down people's efficiency (time on task) and also stop people from being effective (task completion)!
Hey Nikki! Great article, as always :) What sample size would you say is required for a quant test and why? Thank you!
Thank you Tamara! Sample size really depends on your margin of error or the confidence interval you are going for. In this article, Jeff gives a fantastic table for reference: https://measuringu.com/sample-size-recommendations/
I usually go for about 25-30 participants for a quant usability test because that gets around a 15% margin of error and that is typically what my stakeholders have felt comfortable with in the past! Hope that helps!
Thank you for getting back to me so fast! It definitely helps!
Hey, I've noticed you listed "the number of errors" in both, efficiency and effectiveness. Why?
So I feel like number of errors falls into both categories -- it can slow down people's efficiency (time on task) and also stop people from being effective (task completion)!