The presence of civilian witnesses and victims in court is central to the effective operation of the criminal justice system. However, there is evidence of significant non-attendance which can result in ineffective and cracked trials. To address this, West Midlands Police Witness Care Unit and the Behavioural Insights Team designed an intervention using behavioural insight principles consisting of (1) a new conversation guide for Witness Care Officers (WCOs); (2) a redesigned ‘Warning Letter’ confirming details of the proceedings; and (3) a new reminder call and SMS. The impact of the new approach was evaluated through a randomised controlled trial in which 36 WCOs were randomly assigned to either “business as usual” (control) or treatment. The evaluation used an intention-to-treat design with implementation guided and encouraged at several points. Subgroup analysis was undertaken to explore whether differential effects were seen for domestic violence cases or between those that were victims and witnesses. Results indicated that the treatment approach was directionally positive in all cases, but that the increase in attendance was not statistically significant. This is in line with findings of other similar research in this area.

中文翻译：

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法庭上的证词：一项随机对照试验，用于说服证人和受害者参加审判的艺术和科学

平民证人和受害者出庭对于刑事司法系统的有效运作至关重要。但是，有证据表明大量缺勤会导致无效且破裂的审判。为了解决这个问题，西米德兰兹郡警察证人护理处和行为洞察小组使用行为洞察原则设计了一项干预措施，其中包括：（1）新的证人护理人员谈话指南；（2）重新设计的“警告信”，以确认诉讼程序的详细信息；（3）新的提醒电话和短信。通过一项随机对照试验评估了新方法的影响，该试验将36名WCO随机分配给“照常营业”（对照）或治疗。评估采用了意向性治疗设计，并在几个方面对实施进行了指导和鼓励。进行了亚组分析，以探讨在家庭暴力案件中还是在受害者和证人案件之间是否看到了不同的影响。结果表明，在所有情况下，该治疗方法在方向上都是阳性的，但是出勤率的增加在统计学上并不显着。这与该领域其他类似研究的发现是一致的。