Validity and reliability of GRS-S in sample of teachers and parents – a Czech Contribution

One of the goals of this study was to evaluate the factor structure of the Czech translation of the Gifted Rating Scales-school form (GRS-S; Pfeiffer &amp; Jarosewich, 2003) and to investigate differences in factor structure between teachers (<i>n</i> = 137) and parents (<i>n</i> = 277, of which 256 were mothers). To this end, ten alternative models were tested, each twice – with either continuous or ordinal responses. Three models were found to exhibit acceptable fit and interpretability – the original six-factor model, a bi-factor model with six specific factors, and a bi-factor model with six uncorrelated specific factors and three correlated general factors. The factor structure was comparable for both parent and teacher raters. High correlations between the factors suggest that teacher ratings might be subject to a halo effect, resulting in difficulty to differentiate between the subscale’s purported areas of interest. Further, the concurrent validity of the GRS-S with tests of intelligence (WJ IE II COG or CFT 20-R) and mathematical achievement (TIM^3-5) was evaluated. Ratings on the GRS-S made by teachers show a closer relationship with both criteria than ratings made by parents, although in both cases the relationship with intelligence test scores is closer. Finally, test-retest reliability over a period of multiple months (median 93 days) of the GRS-S was estimated on a sub-sample of teachers (<i>n</i> = 88) and was concluded to be quite high for all GRS-S subscales (<i>r</i> = .84 - .87).