Psychologia 15(3), 290–315, 2008Georgios D. Sideridis,1 Angeliki Mouzaki,1 Athanassios Protopapas,2 & Panagiotis Simos1
The purpose of the present study was to examine the psychometric properties of a new measure of spelling achievement. Using a large sample of schoolchildren from Grades 2–4 (N=580), results pointed to the existence of one latent spelling dimension, which was verified across grade and using multiple measurement points. Furthermore, indices of reliability and internal consistency were adequate suggesting the stability of the instrument. A secondary purpose of the present study was to examine the presence of language biases across cultural backgrounds. A series of Differential Item Functioning tests were conducted to examine whether specific words were significantly more difficult for children of immigrants compared to Greeks. By applying the Rasch model, results indicated that most words were not significantly more challenging for immigrant students than for Greeks. Finally, a new ordering of the scale was proposed on the basis of calculated item difficulties.