Is an expert’s opinion based on hearsay?

Notwithstanding that firm position, expert’s opinions ordinarily contain an element of a hearsay and are based not only upon the personal experience of the expert but the conclusions reached by him as a result of his studies and those of others. In Wilband v. R., 1966 CanLII 3 (SCC), [1967] S.C.R. 14, 60 W.W.R. 292, 2 C.R.N.S. 29, [1967] 2 C.C.C. 6, Fauteux J. said at p. 21: … to form an opinion according to recognized normal psychiatric procedures, the psychiatrist must consider all possible sources of information, including second-hand source information, the reliability, accuracy and significance of which are within the recognized scope of his professional activities, skill and training to evaluate … The value of a psychiatrist’s opinion may be affected to the extent to which it may rest on second-hand source material; but that goes to the weight and not to the receivability in evidence of the opinion, which opinion is no evidence of the truth of the information but evidence of the opinion formed on the basis of that information.