TY - JOUR
AU - Perry, Norman C.
AB - IN SYSTEMATIC ERROR ESTIMATES OF A PHI COEFFICIENT 1 ALFRED F. HERTZKA of Southern California University WILLIAM B. MICHAEL The RAND Corporation and NORMAN C. PERRY San State Jose College IN a and Michael formula by Perry (3) previous paper been for the of a coefficient has estimation what developed phi be for an entire criterion from coefficients would group phi from use of of but variable extreme computed equal, groups of the total In in proportions sample. item-analysis procedures, which such a formula be it was assumed that might employed, the total of criterion scores would be as distribution normal, well as the distribution of the variable constituting response behavior to the item. Such an dichot- assumption underlying omization a direct means for the coefficient permits relating phi to the coefficient of tetrachoric correlation use of a set through of tables Pearson in which the volumes of (2) developed by the normal surface are The estimate2 was bivariate presented. as follows: given the of individuals in each of two extreme where proportion groups; in found the two ordinates the unit normal curve YP’ = equal at the two centile and 1oo(1 - sep- points, ioop’ p’), This constitutes 
TI - Systematic Error in Estimates of a Phi Coefficient
JF - Educational and Psychological Measurement
DO - 10.1177/001316445201200210
DA - 1952-07-01
UR - https://www.deepdyve.com/lp/sage/systematic-error-in-estimates-of-a-phi-coefficient-AZ81uaX8OS
SP - 285
EP - 292
VL - 12
IS - 2
DP - DeepDyve
ER -