ABSTRACT
Becausethemajorpurposeofintelligencetestsistopredictachievement,the correlationbetweenintelligencetestscores(IQs)andachievementisfrequentlyexamined toestimatepredictivevalidity.Insuchstudies,theachievementmeasureiscalledthe "criterion."2(Thewordcriterionmeansstandard;thus,weareusingthepredictionof achievementasthestandardforjudgingthevalidityofanIQtest.)Correlationcoefficients inpredictivevaliditystudiesareusuallypositiveinvalue,rangingfrom0.00(novalidity) to1.00(perfectvalidity).3SeeAppendixAtoreviewthemedian,correlationcoefficient andpercentageof varianceaccountedforbeforeattemptingthisexercise.
