Generalizations and Reference Classes
Philosophical Foundations of Evidence Law (Oxford University Press, Christian Dahlman, Alex Stein & Giovanni Tuzet eds.), Forthcoming
22 Pages Posted: 13 Oct 2020
Date Written: October 2020
Legal scholarship exploring the nature of evidence and the process of juridical proof has had a complex relationship with formal modeling. An example of this complex relationship concerns attempts by scholars to use mathematical models to quantify the probative value of evidence in order to study decision-making from that perspective. As with earlier attempts to apply probability theory to juridical proof, this scholarship is interesting, instructive, and insightful. However, it also suffers from a deep conceptual problem that makes ambiguous the lessons that can be drawn from it — the problem of reference classes.
In this chapter, we examine the implications of the reference-class problem for attempts to model the probative value of items of evidence. This chapter makes three contributions. First, and most importantly, it is a further demonstration of the problematic relationship between algorithmic tools and aspects of legal decision-making. Second, it points out serious pitfalls to be avoided for analytical or empirical studies of juridical proof. Third, it indicates when algorithmic tools may be more or less useful in the evidentiary process. At the highest level of generality, this chapter is another demonstration of the very complex set of relationships involving human knowledge and rationality, on the one hand, and attempts to reduce either to a set of formal concepts, on the other.
Keywords: evidence, statistical evidence, probative value, likelihood ratio, reference-class problem
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