title: What we have learned.
authors.affiliation: Department of Psychology,Carnegie Mellon University.
authors.forename: Brian
authors.initials: B
authors.lastname: Macwhinney
mesh_terms: D002648:Child; D002663:Child Language; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D007804:Language Development; D010506:Periodicals as Topic / Q000266:history; D012106:Research / Q000266:history