What is actuarial evidence in the context of lump sum awards?

The matter of actuarial evidence received some attention in the judgment of Dickson J. in Andrews v. Grand & Toy, supra, at p. 581: “The apparent reliability of assessments provided by modern actuarial practice is largely illusionary, for actuarial science deals with probabilities, not actualities. This is in no way to denigrate a respected profession; but it is obvious that the validity of the answers given by the actuarial witness, as with a computer, depends upon the soundness of the postulates from which he proceeds. Although a useful aid and a sharper tool than the ‘multiplier-multiplicand’ approach favoured in some jurisdictions, actuarial evidence speaks in terms of group experience. It cannot and does not purport to speak as to the individual sufferer. So long as we are tied to lump-sum awards, however, we are tied also to actuarial calculations as the best available means of determining amount.”