Explaining the Strength of Evidence
Bernard Robertson, G.A. Vignaux, Charles E.H. Berger · 2016
This chapter focuses on the individual item of evidence in isolation. It recommends a way of giving scientific evidence that complies with logic and makes clear to the court exactly how much the evidence is worth. Part of the task of expert witnesses should be to explain how the court is helped by the evidence given. Expert witness not only gives the correct value for the evidence but tells the jury what to do with it, whereas it is not self-evident what is to be done with a likelihood ratio (LR). The expert is going beyond presenting the strength of his own evidence and discussing how the jury should reason about evidence in general. The chapter recommends that witnesses give evidence in a way that makes clear that the role of their evidence is to affect the prior odds assessed on the basis of the other evidence in the case.