ABSTRACT
An expert gives his opinion on the basis of facts in a particular case, but those facts must themselves be proved by admissible evidence. However, if the rule against hearsay were strictly applied, an expert would often be prevented from giving an opinion because his reasoning and conclusions will be governed by matters that he has learned in the course of his training and experience, either from what he has read or from others who share his specialisation. The courts have therefore relaxed the hearsay rule to take this into account. So, for example, an expert in property valuations is not confined to giving evidence based on comparables of which he has first hand knowledge. Of course, a surveyor who is asked to express a view on the open market value of a particular property will have regard to any relevant personal experience. But he will also have regard to the sales experience of his office, whether that is within his own first hand knowledge or not, and to all sources from which information can be obtained about market trends and conditions.11
