Reliability and validity of mothers' developmental estimates for children between 4 and 41 months

The feasibility of mothers estimating their own children's development is explored in this paper. Construction, reliability and validity of a mothers' developmental inventory for children from 4 months to 41 months is described. The inventory consists of six subtests: Gross Motor, Fine Motor, Language Expression, Language Comprehension, Personal‐Social Competence and Self Help. A preliminary version of the inventory was item analyzed on a sample of 105 mothers of 4 to 37 months old children. This reduced the inventory to 164 items with satisfactory reliability and age discrimination on half‐year intervals. The list was cross‐validated on a sample of 275 mothers, for which medians of alpha coefficients for the six subtests ranged from 0.69 to 0.96, with most (26 out of 36) coefficients being 0.77 or higher. Again, the age discrimination was satisfactory, although floor effects appeared on four subtests for children younger than 12 months and ceiling effects on two subtests for children older than 24 months.