Validity of the Developmental Test of Visual-Motor Integration Supplemental Developmental Test of Visual Perception

Visual perceptual skills of school-age children are often assessed using the Supplemental Developmental Test of Visual Perception of the Developmental Test of Visual-Motor Integration. The study purpose was to consider the construct validity of this test by evaluating its scalability (interval level measurement), unidimensionality, differential item functioning, and hierarchical ordering of its items. Visual perceptual performance scores from a sample of 356 typically developing children (171 boys and 185 girls ages 5 to 11 years) were used to complete a Rasch analysis of the test. Seven items were discarded for poor fit, while none of the items exhibited differential item functioning by sex. The construct validity, scalability, hierarchical ordering, and lack of differential item functioning requirements were met by the final test version. Since 7 test items did not fit the Rasch analysis specifications, the clinical value of the test is questionable and limited.