On the importance of considering heterogeneity in witnesses’ competence levels when reconstructing crimes from multiple witness testimonies
On the importance of considering heterogeneity in witnesses’ competence levels when reconstructing crimes from multiple witness testimonies
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关于从多个证人证词重建犯罪时考虑证人能力水平异质性的重要性
DOI：
10.1007/s00426-016-0802-1
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
J. Musch
中科院分区：
文献类型：
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作者：
Berenike Waubert de Puiseau;Sven Greving;André Aßfalg;J. Musch
汇总多个证词的信息可能会改善犯罪重建。然而，不同的聚合方法是可用的，哪种方法是最适合聚合多个观测缺乏研究。此外，很少有人知道如何在个人证词的准确性差异影响竞争性的汇总程序的性能。我们调查了涉及多个人证词的基于聚合的犯罪重建的优越性，以及这种优越性是否随证人数量和证人准确报告其观察结果的能力的异质性程度而变化。此外，我们还研究了能力水平的异质性是否对两种聚合程序的相对准确性产生了差异性影响：一种是简单的多数规则，它忽略了个体差异，另一种是更复杂的一般孔多塞模型（Romney et al.，Am Anthropol 88（2）：313-338，1986; Batchelder和Romney，Psychometrika 53（1）：71-92，1988），其考虑了个体之间的能力差异。121名参与者观看了一个模拟犯罪，随后回答了128个关于犯罪的真/假问题。我们实验生成组的证人具有同质或异质的能力。无论是多数规则和一般孔多塞模型提供了更准确的重建所观察到的犯罪比个人的证词。涉及多个人证词的综合犯罪重建的优越性随着证人人数的增加而增加。犯罪重建是最准确的能力是异质性和聚合的基础上，一般孔多塞模型。我们认为，一个正式的聚合应该考虑更多的时候，目击者的证词进行评估，一般孔多塞模型提供了一个很好的框架，这样的聚合。
Aggregating information across multiple testimonies may improve crime reconstructions. However, different aggregation methods are available, and research on which method is best suited for aggregating multiple observations is lacking. Furthermore, little is known about how variance in the accuracy of individual testimonies impacts the performance of competing aggregation procedures. We investigated the superiority of aggregation-based crime reconstructions involving multiple individual testimonies and whether this superiority varied as a function of the number of witnesses and the degree of heterogeneity in witnesses’ ability to accurately report their observations. Moreover, we examined whether heterogeneity in competence levels differentially affected the relative accuracy of two aggregation procedures: a simple majority rule, which ignores individual differences, and the more complex general Condorcet model (Romney et al., Am Anthropol 88(2):313–338, 1986; Batchelder and Romney, Psychometrika 53(1):71–92, 1988), which takes into account differences in competence between individuals. 121 participants viewed a simulated crime and subsequently answered 128 true/false questions about the crime. We experimentally generated groups of witnesses with homogeneous or heterogeneous competences. Both the majority rule and the general Condorcet model provided more accurate reconstructions of the observed crime than individual testimonies. The superiority of aggregated crime reconstructions involving multiple individual testimonies increased with an increasing number of witnesses. Crime reconstructions were most accurate when competences were heterogeneous and aggregation was based on the general Condorcet model. We argue that a formal aggregation should be considered more often when eyewitness testimonies have to be assessed and that the general Condorcet model provides a good framework for such aggregations.