Exploratory Testing

• The plainest definition of exploratory testing is test design and test execution at the same time.
• A good exploratory tester will write down test ideas and use them in later test cycles. 
• To the extent that the next test we do is influenced by the result of the last test we did, we are doing exploratory testing. We become more exploratory when we can't tell what tests should be run, in advance of the test cycle, or when we haven't yet had the opportunity to create those tests. 
• If we are running scripted tests, and new information comes to light that suggests a better test strategy, we may switch to an exploratory mode (as in the case of discovering a new failure that requires investigation)
• Conversely, we take a more scripted approach when there is little uncertainty about how we want to test, new tests are relatively unimportant, the need for efficiency and reliability in executing those tests is worth the effort of scripting, and when we are prepared to pay the cost of documenting and maintaining tests.
• But exploratory testers take the view that writing down test scripts and following them tends to disrupt the intellectual processes that make testers able to find important problems quickly.
• I can imagine testing situations where efficiency and repeatability are so important that we should script or automate them. For example, in the case where a test platform is only intermittently available,
• Exploratory testing is especially useful in complex testing situations, when little is known about the product, or as part of preparing a set of scripted tests. 
• whereas scripts, because they don’t change, tend to become less powerful over time. They fade for many reasons, but the major reason is that once you’ve executed a scripted test one time and not found a problem, the chance that you will find a problem on the second execution of the script is, in most circumstances, substantially lower than if you ran a new test instead
• In freestyle exploratory testing, the only official result that comes from a session of ET is a set of bug reports. 
• In session-based test management, each session of ET also results in a set of written notes that are reviewed by the test lead.
• You need to provide rapid feedback on a new product or feature.
• ƒ You need to learn the product quickly.
• ƒ You have already tested using scripts, and seek to diversify the testing.
• ƒ You want to find the single most important bug in the shortest time.
• ƒ You want to check the work of another tester by doing a brief independent
• investigation.
• ƒ You want to investigate and isolate a particular defect.
• ƒ You want to investigate the status of a particular risk, in order to evaluate the need for
• scripted tests in that area.