Quality of childcare and otitis media: Relationship to children's language during naturalistic interactions at 18, 24, and 36 months Lynne Vernon-Feagans a, ⁎ , Megan M. Hurley b , Kristine M. Yont c , Patricia M. Wamboldt d , Amy Kolak e a The University of North Carolina at Chapel Hill, USA b University of Maryland College Park, USA c Harvard University Graduate School of Education, USA d The Pennsylvania State University, USA e The University of Michigan, USA Available online 19 January 2007 Abstract The purpose of this study was to examine the relationship between the quality of childcare and experience with otitis media (middle ear disease) as they relate to children’s early naturalistic language development. Sixty children were followed longitudinally from childcare entry in the first year of life until three years of age. Half the children were in higher quality childcare and half in lower quality childcare, but parent demographics, like education and income, were not associated with the quality of the childcare. Experience with otitis media was monitored weekly in the childcare setting. Naturalistic language samples were collected at 18, 24, and 36 months of age and coded for a variety of syntactic, morphological and semantic markers of language development. Results suggested that children in higher quality care were more advanced on most of the measures of language, especially at 24 and 36 months of age. Children in lower quality care became progressively further behind the children in higher quality care on all language measures. This was especially true for vocabulary, with children in higher quality care having double the number of different words by 36 months as compared to the children in lower quality care. There were no main effects or interactions for experience with otitis media over the first three years. © 2007 Elsevier Inc. All rights reserved. Keywords: Childcare quality; Language development; Otitis media; Dual earner families; Expressive language; Toddlerhood 1. Introduction There has been much recent interest in the effects of variations in quality of child care during the first few years of life (NICHD Early Child Care Research Network, 2005; Vandell, 1997), not only because so many infants are in childcare, but also because there is increased understanding of the importance of developmental advances, especially in Journal of Applied Developmental Psychology 28 (2007) 115 – 133 ⁎ Corresponding author. 301K Peabody Hall (#3500) University of North Carolina, Chapel Hill, NC 27599, USA. E-mail address: lynnevf@email.unc.edu (L. Vernon-Feagans). 0193-3973/$ - see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.appdev.2006.12.003