EDUCATIONAL AND PSYCHOLOGICAL MEASUREMENT

Based on data from 783 primary-grade children, results of princi-pal component factor analyses of the Raven Coloured Progressive Matrices are reported. Analyses were done using phi coefficients, phi/phi max ratios, and tetrachoric correlation coefficients. The re-sults indicated that phi/phi max coefficients and tetrachoric correla-tions yielded identical factor patterns that were not affected by item difficulty. Factors derived from phi coefficients tend to be, at least partially, an artifact of item difficulty. Regardless of the coefficient used, three factors were identified. For phi/phi max and tetrachoric correlation coefficients the three dimensions were identified as: Clo