This document discusses exploratory testing and defines it as "Any testing to the extent that the tester actively controls the design of the tests as those tests are performed and uses information gained while testing to design new and better tests." It describes how all testers do some exploratory testing. Exploratory testers rely on a variety of knowledge, including knowledge of specific domains, risks, and testing techniques. Exploratory testing can differ based on a tester's personality and experiences. Questioning strategies like the Phoenix Checklist can help exploratory testers generate effective questions to test software.