CONTENTS 
XIV 
VALIDATION OF THE MEASURING INSTRUMENTS (Concluded) 174 
Correlation: Product-moment formula; method of rank differ- 
ences; fourfold table method; Pearson biserial r; correlation 
ratio. Coefficient of mean square contingency. Coefficient of as- 
sociation. Probable errors of measures of correlation. Inter- 
pretation of the size of the correlation coefficient. 
XV 
PREDICTION OF VOCATIONAL SUCCESS +:+::tcsssscrveeese 2 J 
Prediction based on group comparison. Critical scores and 
critical sections. 
XVI 
PrEDICTION OF VOCATIONAL Success (Concluded) ...... 197 
Prediction based on correlation. Regression line and regression 
equation. Standard error of estimate. Percentile curves. 
XVII 
PREDICTION BY COMBINED SCORES +1::vcvvevnuannennss 2 
Total scores based on group comparisons. Weighting critical sec~ 
tions. Total scores based on the establishment of correlation. 
Multiple correlation coefficient and multiple regression equa- 
tion. Other methods of combining scores. 
XVIII 
Economic VALUE OF THE EXAMINATIONS .............. 2I} 
Necessity for comparison of old and new methods of selection. 
Relative predictive accuracy. Relative economic value. 
XIX 
THE EXAMINATIONS AT WORK +ovsuser=z-tl:zrrrtns es BEE 
Installation: the examiner; the forms; the room; the procedure; 
the examiner as interviewer. Maintenance: modifications of 
procedure and standards. 
REFERENCES vais vss nv evs nism vsnassnensrsrerinsss Bley 
TABLES  .ncusrt ens names onniinessnsvnrsess savas es vi 240 
DDE a xe vies ins sans sien sne veins dentine sven eewsenl. 205 
Xi 
{QC 
20% 
2927