Reliability and validity of the Southern California Ordinal Scales of Development for a sample of young children with disabilities

The primary purpose of this study was to investigate the reliability and validity of the Southern California Ordinal Scales of Development (SCOSD). The SCOSD is a criterion-referenced test that assesses six domains of development and was designed for use with children with disabilities. Results found that the SCOSD alpha internal consistency coefficients ranged from .94 to .98; percent agreement between raters ranged from 85% to 100%; and interrater correlations ranged from .96 to .99. Strong intercorrelations were found between the SCOSD and standardized domain-specific instruments (.65 to .92), providing evidence of concurrent validity. The secondary purpose was to investigate patterns of development across domains of the children's functioning. As expected, results revealed a hierarchy of skill development, with the children showing relatively less development in gross-motor skills and practical abilities.