Scientists and jurists may appear to speak the same language, but they often mean very different things. The use of statistics is basic to scientific endeavors. But judges frequently misunderstand the terminology and reasoning of the statistics used in scientific testimony. The way scientists understand causal inference in their writings and practice, for example, differs radically from the testimony jurists require to prove causation in court. The result is a disconnect between science as it is practiced and understood by scientists, and its legal use in the courtroom. Nowhere is this more evident than in the language of statistical reasoning.
Unacknowledged difficulties in reasoning from group data to the individual case (in civil cases) and the absence of group data in making assertions about the individual (in criminal cases) beset the courts. Although nominally speaking the same language, scientists and jurists often appear to be in dire need of translators. Since expert testimony has become a mainstay of both civil and criminal litigation, this failure to communicate creates a conundrum in which jurists insist on testimony that experts are not capable of giving, and scientists attempt to conform their testimony to what the courts demand, often well beyond the limits of their expertise.