EMPLOYMENT PSYCHOLOGY 
56 
consists of taking small parts, placing them in the proper 
position, and then either hammering, screwing, pushing, 
or springing them together. The successful assembler 
is therefore one who is possessed, to begin with, of unusual 
manual dexterity. A clumsy fingered person loses a dis 
astrous amount of time at this work, for any natural 
awkwardness has hundreds of opportunities to repeat 
itself in the course of a day. In order to detect the 
presence or absence of the necessary ability, the so- 
called manual dexterity tests were devised. They consist 
of a form board with a row of pieces of graduated size 
cut out and the pieces left fitting loosely. In giving the 
test, the pieces are turned into the cover of the board 
and left in their exact order, after which the subject 
is asked to put them back into their proper spaces as 
expeditiously as possible. This is tried first with the 
right, then with the left, then with both hands. The 
pieces are in some cases quite large, in others quite small, 
just as in assembling, certain operations consist of putting 
together very minute and delicate parts, while others have 
to do with larger parts. In every case, the pieces were 
graduated in size and the subject was always required 
to work from the largest to the smallest. This served 
the useful purpose of increasing the difficulty of the test 
by degrees, thereby making it unnecessary to upset the 
subject by starting him suddenly at a difficult and novel 
task. 
Another quality required by the successful assembler is 
the ability to pick up a part, size it up, and then decide 
just where it belongs and how it shall be placed there. 
In some cases it is the ability to size up a space and then 
pick up the proper piece for that space. In many cases, 
a very fine discrimination of shapes and spaces is required