Metacognition and Knowledge in Forensic Science - Experiment 4

Forensic evidence, particularly DNA analysis, holds significant weight in juror decision-making and is often perceived as nearly infallible (Cashman & Henning, 2012; Kaye, 2010). This perception highlights the necessity for jurors to possess an accurate understanding of forensic processes to make well-informed judgments. However, the extent to which individuals accurately assess their own knowledge of forensic science remains underexplored. One factor that is frequently suggested to sway jurors’ perceptions is the consumption of crime and forensic-related media. Television shows like CSI have popularised forensic science, potentially shaping viewers’ expectations about its capabilities and precision (Schweitzer & Saks, 2007; Alldredge, 2015). This phenomenon, referred to as the “CSI effect,” suggests that exposure to dramatised forensic procedures may lead individuals to develop heightened expectations regarding the reliability and comprehensiveness of forensic evidence in real-world settings. However, another reason that individuals might overestimate their knowledge of forensic processes is that they believe they understand complex procedures more thoroughly than they actually do. This tendency, known as the illusion of explanatory depth (Rozenblit & Keil, 2002), could lead jurors to place greater trust in forensic evidence, thereby influencing their verdicts. While previous research has examined the relationship between media consumption and juror expectations, there is limited evidence directly linking crime media viewing to both actual and perceived knowledge and its overestimation regarding forensic processes. Current studies often rely on self-reported measures of media consumption as a proxy for knowledge, which do not directly assess what participants’ actually know or think they know of forensic science. This gap highlights the need for research that not only measures self-assessed knowledge but also evaluates actual knowledge to identify discrepancies. By directly assessing both perceived and actual knowledge, we can better understand how media exposure and prior knowledge influence jurors’ perceptions and reliance on forensic evidence. The present study, following on from our previous experiment (https://osf.io/vgfaw/overview), aims to address this gap by investigating whether individuals overestimate their knowledge of forensic evidence collection and analysis, and how this overestimation is influenced by crime media consumption and scientific reasoning abilities. Using a fully within-subjects experimental approach, we will directly measure both perceived and actual knowledge, and examine the moderating roles of media consumption and reasoning skills. Following on from our previous experiment where we asked participants to describe their knowledge of forensic and other scientific processes in the form of an open text box, the knowledge elicitation task in this experiment involves participants expressing their knowledge by answering 10 multiple-choice questions on the target topic. Each question has four possible responses, but only one correct, “ground truth” answer. Participants are required to answer all questions to progress. A key contribution of this study is the inclusion of an intervention where participants are asked to directly demonstrate their knowledge of the probed concept. This task, inspired by research on the illusion of explanatory depth (Rozenblit & Keil, 2002), is designed to calibrate participants’ perception of their own knowledge by requiring them to articulate, and thereby confront, their own understanding. By doing so, the intervention may help participants recognise knowledge gaps and reduce overconfidence, leading to a more accurate self-assessment. Consequently, this calibrated self-knowledge could potentially enhance their ability to evaluate forensic evidence more effectively in legal contexts, although this study does not directly measure legal outcomes.