Ad hoc testing is a commonly used term for software testing performed without planning and documentation.
The tests are intended to be run only once, unless a defect is discovered.
Ad hoc testing is a part of exploratory testing, being the least formal of test methods.
In this view, ad hoc testing has been criticized because it isn't structured, but this can also be a strength: important things can be found quickly.
It is performed with improvisation, the tester seeks to find bugs with any means that seem appropriate. It contrasts to regression testing that looks for a specific issue with detailed reproduction steps, and a clear expected result. Ad hoc testing is most often used as a complement to other types of testing.
“Ad Hoc” 原意是指 “特定的，一次性的”；就是为了某一个特定目的进行的测试，就这一次，以后一般也不会重复测试或是尝试性测试某种情况，来检测是否有问题.
所以并非像许多测试人员所讲的是”猴子测试”，误理解了什么是Ad Hoc Testing；正确的测试应是在测试过程中， “ad hoc”测试可以用来衡量当前测试用例的完备性，设计某些特定的，一次性的测试用例，去检查在现有测试用例之外的问题，假如测试时，未发现什么问题，说明现有的测试用例是比较完备的，反之，则不是。