THE VOCATIONAL VALUE OF TESTS 175 
discover these facts. Until they are known, no intelligent 
choice can be made. For instance, when a boy, either 
"within the organization or without, applies for admission 
to the apprentice course, a course which occupies a period 
°f years and which is very costly, the question as to 
"whether this boy has the necessary prerequisite education 
and the natural ability to succeed is sure to arise. He has 
undoubtedly had some education, but whether his educa 
tion has gone far enough, or whether he has profited by his 
educational opportunities to the extent of being able to 
handle the necessary mathematical problems, is a matter 
which must be carefully determined. In addition to this 
it is necessary to know whether the boy possesses the 
natural ability which will enable him to succeed as an 
a pprentice. How shall these two very important facts be 
determined? This is just the question for which psy 
chological tests provide the answer. 
All tests may be divided roughly into two kinds: Those 
designed to discover an individual’s degree of innate 
ability in certain directions, and those designed to measure 
the extent and quality of an individual’s previous training 
and acquired ability. This distinction is by no means a 
dear and sharp-cut one, for every test whatsoever involves 
to some extent both natural or innate ability and the 
ability due to training and education. The tests described 
J n preceding chapters have already made this fact clear. 
However, for practical purposes, tests may be divided into 
these two general kinds. When, therefore, the question of 
■Vocational training or selection arises, the application of 
these tests makes it possible to discover what the natural 
and acquired abilities of an individual are and under 
which of the four heads given he is to be classified. Let 
Us take, for instance, the case of the candidate for appren-