Regina v Bonython: 1984

(South Australia Supreme Court) The court considered the basis for deciding whether a proposed witness was an expert.
Held: It is for the judge to determine whether a witness is competent to give evidence as an expert and for that purpose there are two questions for the judge to decide: ‘The first is whether the subject matter of the opinion falls within the class of subjects upon which expert testimony is permissible. This . . may be divided into two parts: (a) whether the subject matter of the opinion is such that a person without instruction or experience in the area of knowledge or human experience would be able to form a sound judgment on the matter without the assistance of witnesses possessing special knowledge or experience in the area, and (b) whether the subject matter of the opinion forms part of a body of knowledge or experience which is sufficiently organised or recognised to be accepted as a reliable body of knowledge or experience, a special acquaintance with which by the witness would render his opinion of assistance to the court. The second question is whether the witness has acquired by study or experience sufficient knowledge of the subject to render his opinion of value in resolving the issues before the court.
An investigation of the methods used by the witness in arriving at his opinion may be pertinent, in certain circumstances, to the answers to both the above questions . . Where the witness possesses the relevant formal qualifications to express an opinion on the subject, an investigation on the voir dire of his methods will rarely be permissible on the issue of his qualifications. There may be greater scope for such examination where the alleged qualifications depended upon experience or informal studies… Generally speaking, once the qualifications are established, the methodology will be relevant to the weight of the evidence and not to the competence of the witness to express an opinion…’
[1984] 38 SASR 45
Cited by:
ApprovedDoughty v Ely Magistrates’ Court and Another Admn 7-Mar-2008
The claimant sought judicial review. He practised giving evidence as to the operation of traffic speed cameras. The defendant magistrates had declined to accept his evidence saying that he was not an expert.
Held: ‘Whether someone is competent . .
[2008] EWHC 522 (Admin)
CitedKennedy v Cordia (Services) Llp SC 10-Feb-2016
The appellant care worker fell in snow when visiting the respondent’s client at home. At issue was the admission and status of expert or skilled evidence.
Held: Mrs Kennedy’s appeal succeeded. ‘There are in our view four considerations which . .
[2016] UKSC 6, [2016] WLR(D) 74, [2016] PIQR P9, 2016 GWD 4-97, 2016 SCLR 203, (2016) 149 BMLR 17, [2016] ICR 325, 2016 SLT 209, [2016] 1 WLR 597, 2016 SC (UKSC) 59, UKSC 2014/0247

These lists may be incomplete.
Updated: 13 December 2020; Ref: scu.267002