Biedermann Alex
University of Lausanne, Faculty of Law, Criminal Justice and Public Administration, School of Criminal Justice, 1015, Lausanne-Dorigny, Switzerland.
Forensic Sci Int Synerg. 2024 Aug 31;9:100548. doi: 10.1016/j.fsisyn.2024.100548. eCollection 2024.
This technical note extends a recent discussion in this journal of the role of validation study data in rational decision making. One argument that has been made in this context, using elements of Bayesian decision theory, is that further aggregation of validation study data into error rates involves a loss of information that compromises rational inference and decision making and should therefore be discouraged. This technical note seeks to explain that this argument can be developed at different levels of detail, depending on the definition of the propositions of interest, the forensic findings to be evaluated (and hence the form of the likelihood ratio), and the characterization of the relative desirability of decision consequences. The analyses proposed here reveal the cascade of abstractions and assumptions into which discussions about the use of validation study results in forensic science have fallen. This reinforces the conclusion that further aggregation of validation study data into error rates is problematic. It also suggests that even if a definition of error rate(s) could be agreed upon and defensively quantified in a given application, we should rethink and possibly adjust our expectations about what exactly error rates can practically contribute to rational modes of reasoning and decision making in legal contexts.
本技术说明扩展了本刊近期关于验证研究数据在理性决策中的作用的讨论。在这一背景下，基于贝叶斯决策理论的要素提出的一个观点是，将验证研究数据进一步汇总为错误率会导致信息丢失，从而损害理性推断和决策，因此应予以反对。本技术说明旨在解释，这一观点可以根据感兴趣命题的定义、待评估的法医鉴定结果（以及似然比的形式）以及决策后果相对可取性的特征，在不同的详细程度上展开。这里提出的分析揭示了在法医学中关于验证研究结果使用的讨论所陷入的一系列抽象和假设。这强化了将验证研究数据进一步汇总为错误率存在问题的结论。它还表明，即使在给定应用中能够就错误率的定义达成一致并进行可靠量化，我们也应该重新思考并可能调整我们对于错误率在法律背景下究竟能对理性推理和决策模式实际做出何种贡献的期望。
