The Validity and Reliability of Test of Gross Motor Development – 3rd Edition in 3-10 Years Old Children in Ahwaz

Abstract
Background and Objective: The TGMD-3 is a process-oriented test to assess children’s motor development. The aim of study was to evaluate the validity and reliability of test for 3-10 years old children in Ahwaz.
Methods: The strategy and design of the research were descriptive-normative and cross-sectional, respectively. 1600children of 3-10 years old were chosen from eight districts of the city using cluster sampling. Research tool was TGMD-3. The Factor analysis, inter-class and Pearson correlation coefficients were used.
Results: CVI shows a range of 0.80 to 1. The internal consistency for the locomotor, ball skills subtests and total TGMD-3 was 0.85, 0.85 and 0.91 respectively; also, the reliability of test-retest was 0.92, 0.94 and 0.95. The intra-rater reliability coefficient for the locomotor, ball skills subtests and total TGMD-3 was 0.98, 0.99 and 0.99 respectively, while inter-rater was 0.97, 0.98 and 0.98, respectively. In order to evaluate the construct validity, Ulrich’s two-factor design was confirmed using CFA. Correlation coefficients of the subtests were highly positive with age.
Conclusion: Considering the confirmation of validity and reliability of TGMD-3, it can be safely used to evaluate the motor development in Ahwaz children. The correlation of subtests with age supported the age discrimination capability and developmental nature of the test. results are limited to current population and could not be considered as a representation of the whole country, Iran. Future studies may evaluate the properties of this test based on the cultural diversity of other regions.