Why You Only Need to Test with 5 Users
https://gyazo.com/d90f4b7e8ff38debc16c00ea96a05499 https://www.nngroup.com/articles/why-you-only-need-to-test-with-5-users/?utm_content=bufferc10d2&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer
それ以上やっても得られるものが少ない。