Psychometric Proprieties of the Slovenian Version of the Test of Gross Motor Development–3

Motor competence as an indicator of gross motor development is characterized by changes in movement patterns and outcomes. The Test of Gross Motor Development-3 consists of six locomotor and seven ball tasks used to assess the quality of fundamental motor skills in children. The purpose of this study is twofold—to produce a Slovenian translation of Test of Gross Motor Development-3 and to evaluate it on a sample of Slovenian children. First, a back translation was carried out with the help of relevant field professionals, thus producing a Slovenian version of Test of Gross Motor Development-3 with excellent content validity. Second, trained assessors rated the video-recorded test tasks of 452 Slovenian children with smaller groups of measured participants repeating the procedure within 2- and 4-week interval to assess reliability. Finally, the collected data were analyzed using several statistical methods. The data showed good to excellent reliability for intrarater, interrater, test–retest reliability, structural validity, and internal consistency for the majority of motor skills, as well as good measurement invariance across genders.