As a result, a group of test methodologists (now calling themselves the Context-Driven School) began using the term "exploratory" seeking to emphasize the dominant thought process involved in unscripted testing, and to begin to develop the practice into a teachable discipline.
Exploratory testing seeks to find out how the software actually works, and to ask questions about how it will handle difficult and easy cases.
The tester configures, operates, observes, and evaluates the product and its behaviour, critically investigating the result, and reporting information that seems likely to be a bug (which threatens the value of the product to some person) or an issue (which threatens the quality of the testing effort).
The main advantage of exploratory testing is that less preparation is needed, important bugs are found quickly, and at execution time, the approach tends to be more intellectually stimulating than execution of scripted tests.
They do not have to complete a current series of scripted tests before focusing in on or moving on to exploring a more target rich environment.
Freestyle exploratory test ideas, when revisited, are unlikely to be performed in exactly the same manner, which can be an advantage if it is important to find new errors; or a disadvantage if it is more important to repeat specific details of the earlier tests.
This can be controlled with specific instruction to the tester, or by preparing automated tests where feasible, appropriate, and necessary, and ideally as close to the unit level as possible.
Replicated experiment has shown that while scripted and exploratory testing result in similar defect detection effectiveness (the total number of defects found) exploratory results in higher efficiency (the number of defects per time unit) as no effort is spent on pre-designing the test cases.