Ad hoc testing is a common term used for software testing performed without planning and documentation.
The test cases or scripts are intended to be run only once, unless a fault is discovered. Ad hoc validation is a part of exploratory testing, comprising the least formal of testing methods. In this aspect, ad hoc testing has been criticised because it isn’t structured, but this can also be a strength: important defects can be found rapidly. It is executed with improvisation, the tester attempts to find bugs with any means that seem appropriate. It contrasts to regression testing that looks for a particular issue with detailed reproduction steps, and a clean-cut expected result. Ad hoc validation is most often used as a complement to other types of software testing.