How many prototypes for user testing? [duplicate]

1. How many times should you test a prototype?
2. Can there be more than one prototype?
3. How many users do you need for user testing?
4. When testing a new prototype How many people do you need to interview Per persona to detect the main usability issues?

How many times should you test a prototype?

Test 2 to 3 prototypes – Don't put too much time and effort into what's “only” the prototype of that solution. It's more useful to have 2-3 rough prototypes to test than have 1 pixel-perfect prototype.

Can there be more than one prototype?

Multiple prototypes give users and clients that something else to compare against – namely an alternative design. Testing multiple designs allows you to gather more objective data, as you can get feedback for multiple designs.

How many users do you need 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.

When testing a new prototype How many people do you need to interview Per persona to detect the main usability issues?

For usability tests, 5 users seem to be the magic number. These 5 users will usually point out the majority of your key usability issues. After your first few tests, you'll usually identify fewer issues with each new test.