James Bach defines Exploratory Testing as “simultaneous learning, test design, and test execution. In other words, exploratory testing is 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.”
In this video, Kari Kakkonen talks about exploratory testing basics, experiences and future. You will find out where exploratory testing is the most useful, how to develop one’s learning and thinking skills to enable exploratory testing, etc.
Video producer: http://testconf.ru/?lang=en
Further reading: Exploratory Testing: Finding the Music of Software Investigation