Jan N Hughes, Qian Cao, Stephen G West, Paula Allee Smith, Carissa Cerda
Effect of retention in elementary grades on dropping out of school early
Journal of school psychology
scores test gross motor development2 tgmd2 czech sample recruited mainstream urban elementary schools compared us normative sample 315 children participated 152 boys age 71 yr sd 03 163 girls age 70 yr sd 03 differences raw score means percentiles evaluated showing differences czech us normative samples standardized us norms tgmd2 generalized czech population without study