"acceptance testing a phase of software testing that is tested, usually by humans, for acceptability and whether or not it fulfills the business requirements. ad-hoc testing informal software testing method that is done without much planning usually as a “sanity check” to see if a piece of code works and intended for immediate feedback. bug A flaw or mistake in a computer program that results in incorrect behavior that may have unintended such as errors or failure. The term predates modern computer systems but was popularized by Grace Hopper who, when working with the Mark II computer in 1946 traced a system failure to a moth stuck in a relay. 46, 81, 151 debug the process of analyzing a program to find a fault or error with the code that leads to bad or unexpected results. 152 debugger a software tool that facilitates debugging; usually a debugger simulates the execution of a program allowing a developer to view the contents of a program as it executes and to “walk” through the execution step by step. 152 edge case a situation or input that represents an extreme value or parameter. exception an event or occurrence of an erroneous or “exceptional” condition that inter- rupts the normal flow of control in a program, handing control over to exception handler(s). 155 fuzzing An automated software testing technique that involves providing invalid or random data as input to a program or piece of code to test that it fails in an expected manner.. integration testing a type of software testing used to determine if the integration of different components or modules works or not. heisenbug a bug in a program that fails to manifest itself under testing or debugging conditions. Derived from the Heisenberg principle which states that you cannot observe something without affecting it, thus tainting your observations.. defensive programming an approach to programming in which error conditions are checked and handled, preventing undefined or erroneous operations from happening in a program. 38, 48, 84"