H. C. Link states that The application of psychological tests in those fields where their value has been verified, is the only method short of the laborious and costly method of trial and error, which makes it possible to discover the exact ability, both innate and acquired, of an individual. Unless these facts are known, it becomes impossible to assign the individual to the work for which he is best fitted or to give him the training which he deserves. Once the potential and actual ability of an individual has been discovered the vocational selection or training of that individual can be decided with a measurable degree of intelligence
