When writing test code, there are moments when you need to convince yourself. “Will the development schedule be delayed because of the test?”, “Is it right to test this?”, “Should I test the content that will be changed in the future?” This lecture shows you various techniques on how to strategically test a simple shopping mall site. After watching the video, I think you will be able to confidently write test code that you can convince yourself. I hope that many people will watch this video and gain confidence in testing.