Research has indeed shown that parents—regardless of socioeconomic status, location, or well-being—give accurate information about their child’s development (Rydz et al., 2005; Squires et al., 1998). Parent report is most accurate if questions are straight-forward and ask about their child’s current, observable behaviors. While there are some parents, such as those with substance abuse issues or severe mental health problems, that may not provide accurate information, most parents can accurately answer simple questions about their child’s current repertoire of behaviors. 

Because parents (and other primary caregivers) have expert knowledge about their child’s abilities and skills, parental involvement in developmental screening important. Several research studies have shown that parents’ observations and report of their children’s development are predictive of developmental delays. Studies published in Topics in Early Childhood Special Education have shown that parents as observers are effective identifiers of children with delays (Diamond, 1993) and that use of parent-completed questionnaires was an accurate way to monitor children’s development (Bricker & Squires, 1989). Furthermore, studies by Frances Glascoe and colleagues (Glascoe, 1997; Glascoe & Dworkin, 1995) showed that parental concerns about language, fine motor, cognitive, and emotional-behavioral development are highly predictive of actual problems. These studies establish parent-report tools, like ASQ-3 and ASQ:SE-2, as an accurate method of developmental screening. In addition, parent-completed tools are time- and cost-efficient, and they help educate parents about typical child development. 

For more detailed information about parent reporting of children’s developmental skills, the following articles are helpful:

• Bricker, D., & Squires, J. (1989). The effectiveness of parental screening of at risk infants: The infant monitoring questionnaires. Topics in Early Childhood Special Education, 9(3), 67–85.
• Diamond, K. (1993). The role of parents' observations and concerns in screening for developmental delays in young children. Topics in Early Childhood Special Education, 13(1), 68-81.
• Diamond, K., & Squires, J. (1993). The role of parental report in the screening and assessment of young children. Journal of Early Intervention, 17(2), 107-115.
• Rydz, D., Shevell, M.I., Majnemer, A., & Oskoui, M. (2005). Developmental screening. Journal of Child Neurology, 20(1), 4–21.
• Glascoe, F.P., & Dworkin, P. (1995). The role of parents in the detection of developmental and behavioral problems. Pediatrics, 95(6), 829–836.
• Glascoe, F.P. (1997). Parents’ concerns about children’s development: Prescreening technique or screening test? Pediatrics, 99, 522–528.
• Glascoe, F.P. (1999). The value of parents' concerns to detect and address developmental and behavioural problems. Journal of Pediatrics and Child Health, 35(1), 1–8.
• Squires, J. (2000). Early detection of development delays: Parents as first level screeners. Journal of Intellectual Disability Research, 44(3 & 4), 471.
• Squires, J., Potter, L., Bricker, D., & Lamorey, S. (1998). Parent-completed developmental questionnaires: Effectiveness with low and middle income parents. Early Childhood Research Quarterly, 13(2), 345-354.
• Tervo, R. (2005). Parent's reports predict their child's developmental problems. Clinical Pediatrics, 44, 601-611.