Objectives

The current review assesses the methodological characteristics of between-subjects experiments, in particular documenting the scenarios and treatments described in each vignette, the extent to which confounds are embedded or accounted for in the design, and the analytic approach to estimating direct and interaction effects.

Methods

We conducted a pre-registered systematic review of 20 publications containing 20 independent studies and 23 vignette scenarios.

Results

We find that the majority of studies rely on non-probability convenience sampling, manipulate a combination of procedural justice elements at positive and negative extremes, but often do not address potential confounds or threats to internal validity. The procedural justice manipulations that combine different elements show relatively consistent associations with a range of attitudinal outcomes, whereas the results for manipulations that test individual components of procedural justice (e.g., voice) are more mixed.

Conclusions

Based on our review, we recommend that future studies using text-based vignettes disaggregate different elements of procedural justice in manipulations, and include a gradient of treatment or behavior (including control) to avoid comparing extremes, to incorporate potential confounders as either fixed covariates or manipulations, and to formally assess the information equivalence assumption using placebo tests.

中文翻译：

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在研究警察程序正义中使用实验性小插曲：系统评价

目标

目前的审查评估了受试者间实验的方法学特征，特别是记录了每个小插曲中描述的场景和处理方法、设计中嵌入或考虑的混淆程度，以及估计直接和交互影响的分析方法。

方法

我们对包含 20 项独立研究和 23 个小插曲场景的 20 篇出版物进行了预先注册的系统评价。

结果

我们发现，大多数研究依赖于非概率便利抽样，在积极和消极的极端情况下操纵程序正义元素的组合，但往往没有解决对内部有效性的潜在混淆或威胁。结合不同元素的程序正义操作显示出与一系列态度结果相对一致的关联，而测试程序正义的各个组成部分（例如，声音）的操作结果则更加复杂。

结论

根据我们的审查，我们建议未来使用基于文本的小插曲的研究分解操作中程序正义的不同元素，并包括处理或行为（包括控制）的梯度以避免比较极端，将潜在的混杂因素纳入固定协变量或操作，并使用安慰剂测试正式评估信息等价假设。