Psychometric Theory

actually alternative forms applied approach assumptions attitudes attribute average correlation centroid method Chapter clusters coefficient alpha computed concerning construct validity content validity correct correlation matrix correlations among items covariance cross products developed dichotomous items discriminant discussed distances distribution domain domain-sampling model employed equal estimate example factor analysis factor loadings Figure formula guessing Guttman scale highly human abilities hypotheses important individual differences inferential statistics interval scale investigations item analysis item-total correlations linear combination mathematical mean measurement error measures of personality multidimensional scaling multiple correlation normal distribution number of items obtained scores partial correlation particular personality traits phi coefficients possible predictive previously problem profiles psychological Q sort ratings ratio scale reliability response styles rotated factors sample self-inventories standard deviation standard scores statements statistical stimuli studies subjects tend theory tion total scores trace lines true scores types usually values variance vectors weights zero