Ideal number of candidates for user-testing

1. What is a good sample size for user testing?
2. How many participants is enough for user testing?
3. Why you should test with 5 users?
4. How do you choose participants for usability testing?

What is a good sample size for user testing?

In summary, research suggests that from three to twenty participants can provide valid results, and a good baseline is between five and ten participants. In general, there should be more participants for more complex, highly critical projects; while fewer participants are necessary when testing more novel designs.

How many participants is enough for user testing?

Summary: Elaborate usability tests are a waste of resources. The best results come from testing no more than 5 users and running as many small tests as you can afford.

Why you should test with 5 users?

In a research study from 2000, Jakob Nielsen and Tom Landauer found that you only need 5 users to test your application in order to identify 75-99% of all usability problems. You only need 3 to 5 users to identify the majority of usability issues.

How do you choose participants for usability testing?

Be able to explain to users how their data and any data generated in the study will (and will not) be used. Know how many users you need to recruit to give a representative sample. Know what type of users will best represent your user base (user personas) Know what (if any) reward you will offer to participants.