THE RELIABILITY AND VALIDITY OF STRUCTURAL MEASURES DERIVED FROM REPERTORY GRIDS

This study examined the reliability and validity of measures derived from repertory grids in a limited domain. Twenty primary school teachers were interviewed at three points over a 12-month period, approximately six months apart, resulting in impressive test-retest stability for most measures. The pattern of construct relationships for individual teachers, operationalized as the mean Coefficient of Convergence, was 0.77 over a 12-month interval. Intensity and the percentage variance accounted for by the first factor (PVAFF) of principal component analysis were highly correlated with values ranging between 0.89 and 0.95 at different phases of the study. They also proved to be stable characteristics of the individual with test-retest reliability for Intensity of 0.87, and 0.73 for PVAFF over a 12-month interval.