APPENDIX 
401 
Rating Formula I 
N- E 
RU 
r, in which 
N = number of units covered 
E =» errors 
RU = the number of units called for by the point of reference, 
r = rating 
For application, see rating of tests 6 and 8. When no fixed time 
is set, but each individual is allowed to complete the test in 
his own time, the equation becomes: 
Rating Formula II 
Ru X RU - E . ,., 
— = r, in which 
RU = the number of units called for by the point of reference, 
in this case, the entire test. 
Ru = reference time per unit, obtained by dividing the refer 
ence time by the reference units (RU). In test 2 this 
would be 35 (reference time) 4- 50 
T = time actually taken by individual (number of cards) or .7. 
For application, see rating of test 2. 
Frequently, accuracy is at a premium, and special emphasis 
is to be placed upon mistakes. This can be done by multiply 
ing E or the number of errors by 2, 3, 4, or whatever value the 
situation calls for. The general practice here is to count each 
error as one unit and each omission as one unit. 
The two equations formulated above can be applied to all 
tests in which time, quantity, and quality are the factors. 
Moreover, each equation can be easily converted from a time 
basis to a quantity basis, and vice versa. This is a great ad 
vantage in handling data obtained under varying circumstances. 
This method of rating may appear complex at the outset but 
a little practice will show it to be extremely simple and easy of 
application. It can be still further simplified by the use of tables.