This article describes the development and validation of the Developmental Snapshot, a 52-item parent questionnaire on child language and vocal communication development that can be administered monthly and scored automatically. The Snapshot was created to provide an easily administered monthly progress monitoring tool that enables parents to…

This paper provides practical guidance for researchers who are designing studies that randomize groups to measure the impacts of interventions on children. To do so, the paper: (1) provides new empirical information about the values of parameters that influence the precision of impact estimates (intra-class correlations and R-squares); (2)…