Understanding expert opinions

Graham Jackson (University of Abertay, UK)

Technological advances have provided experts with powerful, sensitive tools to analyse and discriminate samples. However, the benefits to the criminal justice system of such advanced techniques cannot be realised fully unless the expert is able to form rational, coherent, useful opinion; the expert must also be able to communicate clearly the justification of that opinion to fact-finders. Shortcomings in the formulation and expression of expert opinion has lead in the past to miscarriages of justice and will continue to do so if the basis of expert opinion remains opaque and reliant solely on the bald assertion of expertise.
Using a number of case examples, this talk will explain and explore application of a Bayesian paradigm to expert opinion and illustrate how such opinion may be challenged and critiqued.