Experimental criminology refers to research that uses experiments to evaluate the effects of a policy, program, or intervention in criminal justice. As used here, an experiment is not to be confused with how this word is typically understood by laypeople to mean “the action of trying something new.” In contrast, when used by experimental criminologists, it has a very specific meaning: It is a study that implements the random assignment of units to experimental (E) or control (C) conditions before the introduction of a program, policy, or intervention. An experiment’s main advantage over other research methods is that it provides the greatest assurance that the results achieved are valid. This entry presents a more detailed understanding of experimental criminology by providing a brief history of ...