Use of Bayes’ theorem in data analysis and interpretation

Making questions explicit in propositions, following the laws of logic, and basing the answers on information and expertise are the fundamental principles of forensic interpretation. Additionally, they define the role of the forensic scientist in the criminal justice system. Given the importance of contextual information for the interpretation of evidence, this chapter explains when that information is task-relevant and when it is task-irrelevant and should be kept from the examining scientist. Deviating from logic results in errors of reasoning, which are identified, as are conclusions that suggest more than they actually mean. And finally, guidance is offered for the phrasing of valid and useful propositions that help to address the most relevant issues in the case.