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

The Test of Gross Motor Development – 3rd Edition is a process-oriented test to assess childrens’ motor development. The aim of study was to evaluate the validity and reliability of this test for 3-10 years old children in Ahwaz.
Subjects and The strategy and design of the research were descriptive-normative and cross-sectional, respectively. One thousand and six undred children aged 3-10 years old were chosen from eight districts of the city using cluster sampling. Our research tool was TGMD-3. The Factor analysis, inter-class and Pearson correlation coefficients statistical methods were used.
Content Validity Index 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. In addition, 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 Confirmatory factor analysis. Correlation coefficients of the subtests were highly positive with age.
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. Our results are limited to current population and should 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.