The inherent variability of cases in legal practice in the domain of private law places important constraints on the conclusions to be drawn from observations from actual litigation. Simply put, cases in the domain of private law vary with regard to numerous features (for example, nature of harm, liability standard, level of fault, claims, awards, features of the litigants, and so forth) that may impact the processes that occur within them, yet whose unique contributions to these outcomes are impossible to separate. This notion poses an important challenge for legal theorizing and policy making, as it makes it impossible to ascertain which factors or processes may account for particular desirable or undesirable phenomena in litigation-and impossible to understand, therefore, how legal policy and procedure should be shaped in response. While doctrinal, theoretical approaches and field observations can provide important indications, their inability to provide causal evidence means that initiatives derived from them may be off the mark, and thereby may fail to produce the desired results. Experimental approaches provide a powerful tool to counter such limitations. These approaches seek to minimize or control the variability that characterizes cases in litigation practice, and to tease apart the effects of the numerous features on which they differ. Their means of doing so are laboratory or field experiments, in which actual litigation contexts are adapted or are simulated under controlled circumstances. In these experiments, the many, covarying features that characterize cases in actual litigation are disentangled by isolating particular key features (for example, whether apologies are provided or not) and varying them systematically between cases, while minimizing variability on other factors (for example, between types of tort, level of harm, and so on). Through this approach, the researcher can isolate the unique contributions of particular features or phenomena (for example, apology) to particular outcomes or challenges in legal practice (for example, secondary victimization). Thereby, experimental approaches enable the acquisition of unique causal evidence with