Psychology, Public Policy, and Law, Vol 32(3), Aug 2026, 275-297; doi:10.1037/law0000467
Understanding the level of confidence an eyewitness intends to communicate is important for criminal justice. However, eyewitnesses vary considerably in what they mean—even when using the same phrase—and evaluators vary in their interpretations too. Building on that work, we show how the criminal justice system could leverage where agreement does exist. We produced a tool (a lexicon) for helping eyewitnesses and legal actors to understand how people on average interpret confidence. The tool could be used to guide the communication of eyewitness confidence. Three replications demonstrate that the structure of the produced lexicon is relatively, though not perfectly, consistent across samples and English-speaking cultures. Study 5 shows that eyewitnesses’ numeric translations of phrases from the lexicon when they spontaneously produce them result in similar distributions of meaning as those we obtained from non-eyewitness interpreters in Studies 1–4. Furthermore, the lexicon elicited a similar confidence–accuracy relationship as asking for confidence on a 0%–100% scale or in eyewitnesses’ own words. While one might argue that this suggests reliance on the eyewitness’s own words is sufficient, we argue that research-based evaluations of own-words confidence—here and in prior research—likely overestimate the confidence–accuracy relationship because researchers systematically interpret own-words confidence. In practice, individuals make unaided (and variable) interpretations of verbal confidence judgments. Therefore, our results suggest a lexicon could produce a superior confidence-accuracy relationship in practice. (PsycInfo Database Record (c) 2026 APA, all rights reserved)