Writing and executing detailed test scripts can take a lot of time from both the test engineer and test executioner, so often these tests are automated. Once they are automated, they will fall into the category of system tests and automated UI tests in particular.

This does not necessarily mean that manual tests provide no value or no good return on investment at all. There are just some things that the human eye will catch that a computer will not, such as interfaces that are just not user friendly, misaligned interface elements, and text lines or images that are not fully displayed but get hidden behind other elements.

To catch these errors while not spending large amounts of time on detailed test scripting, exploratory testing might be a solution. In this approach, a tester opens the application and starts investigating those parts of the application that they feel contain the most risks with regard to the upcoming release. While exploring the application, the tester keeps track of which parts of the application they have visited and which test cases they have performed. Meanwhile, the tester also keeps track of new risks they identify or test cases they have not performed yet. In doing so, they are creating a list of covered and uncovered test cases while they are working. It also allows the tester to keep focusing on the most important risk and test cases all of the time. Once the exploratory test run is over, the tester can report on which application areas and test cases have been covered, which have not, and which risks are still not explored at all. This report can be valuable input for a product manager who must decide whether to move forward with a release or not.

A common misconception is that exploratory testing means that a tester is just clicking around to see whether the application is working okay. This is not the case, and the previous paragraphs have shown that exploratory testing is a highly structured activity that requires practice. If performed well, test preparation and test execution are interwoven during an exploratory testing session.

Exploratory testing is a great tool for when there is limited time or the amount of time available for testing is not known upfront. Exploratory testing may yield findings that need to be recorded as defects. How to do this is up next.