ABSTRACT
This chapter deals with the case law as it has developed, principally in Scotland. In Scotland the threshold of admissibility has been set quite low as compared to other common law jurisdictions and the judge in this jurisdiction has, traditionally, exercised a weak ‘gatekeeper function’ to exclude from probation any unsound, invalid or unorthodox opinion. In civil law systems where an inquisitorial rather than adversarial inquiry is the norm, the expert frequently sits on the bench with the judge advising the court like an assessor, as opposed to giving evidence from the witness box in chief and then under cross-examination. In a case, the Inner House of the Court of Session held that ‘an expert’ had erroneously been admitted as a witness in a personal injury case, to express opinions about matters well within the cognisance of the first instance court.
