Various groups were sent an online survey regarding language development milestones for children ages 12-36 months. Given a choice of four ages for each of the 15 language skill statements, participants assigned an age at which they presumed the skill would be present.
Adcock, Kelsie and Hogue, Kelsey, "Adults’ Knowledge About Language Development Milestones for Children Between 12-36 Months of Age" (2016). Scholars Day. 18.