Within legal scholarship there is a tendency to use (perhaps overuse) "paradigm shift" in ways far removed from the process famously described by Thomas Kuhn. Within the field of evidence, however, a phenomenon very similar to a paradigm shift, in the Kuhnian sense, is occurring. Although not on the scale of the transformation from Newtonian to Einsteinian physics or other tectonic shifts in science, the best understanding of juridical proof is shifting from probabilism to explanationism. For literally hundreds of years, proof at trial was assumed to be probabilistic. This assumption was given sustained scholarly attention and support beginning with the 1968 publication of John Kaplan's path-breaking article that generated a rich literature explaining virtually all aspects of juridical proof as probabilistic, from the basic nature of relevancy through the processing of information to the final decision about the facts. Although probabilism quickly became the dominant paradigm, some analytical difficulties were detected quite early ("anomalies" or "irritants" in the words of Kuhn), beginning with L. Jonathan Cohen's demonstration of certain proof paradoxes. These were extended by Ronald Allen, who also demonstrated the incompatibility of Bayesian reasoning with trials and proposed an analytical alternative. Again a complex literature ensued with the defenders of the dominant paradigm attempting to explain away the anomalies or to shield the probabilistic paradigm from their potentially corrosive effects (in what in fact on a very small scale is precisely what Kuhn explained and predicted with respect to paradigm shifts in science). Over the last two decades, these anomalies have become too irritating to ignore, and the strengths of the competing paradigm involving explanatory inferences (referred to as the relative plausibility theory) have become too persuasive to dismiss. Thus the paradigm shift that the field is now experiencing. We provide here a summary of the relative plausibility theory and its improvement on the probabilistic paradigm. As Kuhn noted, not everybody gets on board when paradigms shift; there are holdouts, dissenters, and objectors. Three major efforts to demonstrate the inadequacies of relative plausibility have recently been published. We analyze them here to demonstrate that their objections are either misplaced or unavailing, leaving relative plausibility as the best explanation of juridical proof. It is interesting to note that two of the three critiques

In many areas of life, from hard science to managing one's everyday affairs, explanatory considerations help to guide inference. From the fact that some proposition would explain a given phenomenon we infer that the proposition is true. And when several propositions may explain a given phenomenon we infer the one that best explains it. Quantum mechanics best explains sub-atomic phenomena; evolutionary theory best explains species variations; that George Washington existed best explains the historical record concerning him; and that the Cubs won yesterday best explains why today's newspaper reports that they did. These inferences all share the same structure, typically referred to as "abduction" or "inference to the best explanation." 1 Because legal proof falls somewhere between science and managing one's everyday affairs, it should perhaps not be surprising that the juridical proof process involves similar inferential practices.

This paper discusses mathematical modeling of the value of particular items of evidence. We demonstrate that such formal modeling has only limited use in explaining the value of legal evidence, much more limited than those investigators who construct and discuss the models assume, and thus that the conclusions they draw about the value of evidence are unwarranted. This is done through a discussion of several recent examples that attempt to quantify evidence relating to carpet fibers, infidelity, DNA random-match evidence, and character evidence used to impeach a witness. This paper makes the following contributions. Most important, it is another demonstration of the complex relationship between algorithmic tools and legal decision making. Furthermore, at a minimum it highlights the need for both analytical and empirical work to accommodate the reference-class problem and the risk of failing to do so.

Within legal scholarship there is a tendency to use (perhaps overuse) "paradigm shift" in ways far removed from the process famously described by Thomas Kuhn. Within the field of evidence, however, a phenomenon very similar to a paradigm shift, in the Kuhnian sense, is occurring. Although not on the scale of the transformation from Newtonian to Einsteinian physics or other tectonic shifts in science, the best understanding of juridical proof is shifting from probabilism to explanationism. For literally hundreds of years, proof at trial was assumed to be probabilistic. This assumption was given sustained scholarly attention and support beginning with the 1968 publication of John Kaplan's path-breaking article that generated a rich literature explaining virtually all aspects of juridical proof as probabilistic, from the basic nature of relevancy through the processing of information to the final decision about the facts. Although probabilism quickly became the dominant paradigm, some analytical difficulties were detected quite early ("anomalies" or "irritants" in the words of Kuhn), beginning with L. Jonathan Cohen's demonstration of certain proof paradoxes. These were extended by Ronald Allen, who also demonstrated the incompatibility of Bayesian reasoning with trials and proposed an analytical alternative. Again a complex literature ensued with the defenders of the dominant paradigm attempting to explain away the anomalies or to shield the probabilistic paradigm from their potentially corrosive effects (in what in fact on a very small scale is precisely what Kuhn explained and predicted with respect to paradigm shifts in science). Over the last two decades, these anomalies have become too irritating to ignore, and the strengths of the competing paradigm involving explanatory inferences (referred to as the relative plausibility theory) have become too persuasive to dismiss. Thus the paradigm shift that the field is now experiencing. We provide here a summary of the relative plausibility theory and its improvement on the probabilistic paradigm. As Kuhn noted, not everybody gets on board when paradigms shift; there are holdouts, dissenters, and objectors. Three major efforts to demonstrate the inadequacies of relative plausibility have recently been published. We analyze them here to demonstrate that their objections are either misplaced or unavailing, leaving relative plausibility as the best explanation of juridical proof. It is interesting to note that two of the three critiques

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