$(9$ Points$)$ List three data gathering protocols for usability testing.

$(9$ Points$)$ What is the difference between extreme unit testing with regular unit

testing?

$(10$ Points$)$ Suppose that you are performing usability testing and you would like to

decide on the number of testers. If each user can find $10$ percent of the errors,

calculate the least number of testers you would require for finding $90$ percent of the

errors?