p. 63320. Experts and opinion evidence
- Adrian KeaneAdrian Keaneof the Inner Temple, Barrister, Emeritus Professor of Law, The City Law School, City, University of London, Former Dean of the Inns of Court School of Law
- and Paul McKeownPaul McKeownof Lincoln’s Inn, Barrister, Assistant Professor of Law, The City Law School, City, University of London
Abstract
This chapter discusses the law on experts and opinion evidence. As a general rule, opinion evidence is inadmissible: a witness may only speak of facts that he personally perceived, not of inferences drawn from those facts. However, there are two exceptions to this general rule: (i) an appropriately qualified expert may state his opinion on a matter calling for the expertise that he possesses; and (ii) a non-expert witness may state his opinion on a matter not calling for any particular expertise as a way of conveying the facts that he personally perceived. Experts may also give evidence of fact based on their expertise. The chapter covers the duties of experts and the rules which apply where parties propose to call expert evidence