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The Child Language and Literacy Lab explores questions like "How do children learn words?", "Why is word learning easier for some children than others?", and "What learning conditions make word learning easier, especially for children who need more words to succeed academically and socially?".  We are grateful for the participation of children and families in our research, which take place in schools, in person in the lab, and online (currently, all sessions are online).  Work in the lab has been funded by the National Institutes of Health ( R01DC017156-01 and UL1TR001857), and the University of Pittsburgh Competitive Medical Research and Development Fund and Central Research Development Funds.  The lab is located in Forbes Tower in the Oakland neighborhood of Pittsburgh.  


Dawna Duff, PhD, Reg. CASLPO, SAC(SLP)
Lab Director, Assistant Professor 

 Dawna Duff

Dawna Duff is an assistant professor in the Department of Communication Science and Disorders and directs the Child Language and Literacy Lab. Her primary research interest is understanding individual differences in vocabulary learning and its relationship to reading.  Her particular focus is the semantic aspects of incidental word learning while reading text, a process that is critical to vocabulary growth.  This individual differences approach includes research with typical learners, as well as those with a range disorders affecting language and communication, including developmental language disorder (DLD), dyslexia, and Down syndrome. The group in the Child Language and Literacy Lab uses a combination of approaches, including experimental approaches, analyses of longitudinal data, and both language measures, and eye movement studies.   

Dr. Duff earned her B.Sc. in Physiology and Linguistics from McGill University in Montreal, and her Master of Health Science in Speech Language Pathology from the University of Toronto. She has clinical experience with children in both school and hospital settings. She earned her PhD in Speech and Hearing Science from the University of Iowa before joining the University of Pittsburgh Department of Communication Science and Disorders in 2016.  

Maalavika Ragunathan, M.S, MEd 
Project Coordinator 

Maalavika Ragunathan

Malavika Ragunathan is a project coordinator in the Child Language and Literacy Lab. She manages the research study called Project WORD: Word Learning and Reading Development. Ragunathan graduated from Boston University first with her Masters in Anatomy and Neurobiology, and later in Special Education. She is a certified special educator who has worked in both public and private school settings and has been involved in education research for the last six years.

Research Assistants

Bridget Maloney

Bridget Maloney

Samantha Duffie

Samantha Duffie

Bradley Seltzer

Bradley Seltzer

Isabel Bejjani

Isabel Bejjani


Boy writing in a workbook 

Duff, D., Hendricks, A., Fitton, L., Adlof, S. (2021) Reading and math achievement in children with dyslexia, developmental language disorder, or typical development: Achievement gaps persist from second through fourth grades”   Under review, archived at 

Person jumping across a gap 

Duff, D., & Brydon, M. (2020). Estimates of individual differences in vocabulary size in English: how many words are needed to ‘close the vocabulary gap’?. Journal of Research in Reading, 43(4), 454-481.

Person giving a thumbs up 

Duff, D. (2019). The effect of vocabulary intervention on text comprehension: who benefits?. Language, speech, and hearing services in schools, 50(4), 562-578.

Carrot next to a measuring tape 

Duff, D. (2019). Has vocabulary intervention had an effect? A valid, reliable, and (fairly) quick outcome measure for semantic knowledge. Language, speech, and hearing services in schools, 50(4), 506-517.

Boy holding a book with his mouth open     

Duff, D., Tomblin, J. B., & Catts, H. (2015). The influence of reading on vocabulary growth: A case for a Matthew effect. Journal of Speech, Language, and Hearing Research, 58(3), 853-864.

A doctor with a stethoscope around her neck smiling 

Duff, D., Kohut, K., Norberg, K. (under review) "Short Sentences and Simple Words Aren’t Enough: The Importance of Cohesion in Patient Education Materials".

 An escalator  

McGregor, K. K., Oleson, J., Bahnsen, A., & Duff, D. (2013). Children with developmental language impairment have vocabulary deficits characterized by limited breadth and depth. International Journal of Language & Communication Disorders, 48(3), 307-319.

Two children standing in grass reading a book 

McGregor, K. K., Berns, A. J., Owen, A. J., Michels, S. A., Duff, D., Bahnsen, A. J., & Lloyd, M. (2012). Associations between syntax and the lexicon among children with or without ASD and language impairment. Journal of autism and developmental disorders, 42(1), 35-47.