The Effect of Ambiguous Question Wording on Jurors’ Presumption of Innocence

Research suggests that jurors misunderstand the presumption of innocence. However, past studies have not asked participants to estimate the defendant’s probability of guilt, setting aside the fact of charge and indictment. We conduct two studies to explore the impact of this question wording on estimates of the probability of guilt/innocence by jury-eligible Mturk workers. In Experiment 1 (N = 275), question wording (legal, factual and ambiguous) was varied within participants and revealed significantly higher estimates of innocence in response to the legal than the factual or ambiguously worded question. In Experiment 2 (N = 303), question wording was manipulated between participants both before (prior) and after (posterior) the presentation of evidence. Prior estimates of guilt were significantly lower in the legal than factual or ambiguous conditions. Question wording also predicted posteriors, and these in turn predicted verdicts. These results suggest that imprecise wording may have contributed to concerns about jurors’ understanding of the presumption of innocence, highlighting the need for further research.