College of Liberal Arts

Child Language Research Laboratory
(Laurence B. Leonard, Director)

Since 1978, members of the Child Language Research Laboratory have been conducting studies designed to uncover the nature of language disorders in children.  Progress in understanding these disorders should lead to more effective intervention approaches and to methods of early identification.

For much of this period, the research team has focused on children with specific language impairment (SLI).  These children have significant difficulties acquiring spoken language and are at risk for reading problems when they reach school age.  They are a puzzle because factors often associated with language learning deficits are not present in these children.  Children with SLI show normal hearing, age-appropriate scores on nonverbal tests of intelligence, and no evidence of neurological impairment.  The prevalence of SLI may be as high as 7% during the preschool years.

The studies conducted by the research team have dealt with a wide variety of questions concerning the language comprehension and production abilities of children with SLI.  In recent years, much of this research has concentrated on these children’s apparent difficulty with certain grammatical details.  When these children reach the point of using simple sentences, they often leave out small “grammatical” words (such as is and of)and grammatical endings (such as past tense –ed and possessive ’s) to a greater extent than we see in younger, typically developing children.  These difficulties in constructing sentences often persist at least through the preschool years, and represent one of the ways that children with SLI can be most easily identified.  Our research team has been exploring factors that may be at the heart of these difficulties, as well as methods that might be used to help these children overcome these difficulties more quickly.

One way we are attempting to discover the source of the children’s grammatical difficulties is to examine SLI from a crosslinguistic perspective.  Through the study of children with SLI who are acquiring very different languages, in which grammatical notions such as past tense and possession are expressed in markedly divergent ways, the research team hopes to discover the common denominator – the core of the severe grammatical difficulty.  Thus far, studies of English have been supplemented by investigations of Italian, Hebrew, Swedish, Spanish, Cantonese, and most recently Finnish and Hungarian.  We are fortunate to be working with an excellent group of researchers who are experts in these particular languages. 

We are also conducting a major language intervention study with the aim of discovering effective ways of helping children learn to use grammatical forms in a consistent manner.  In this project, children participate in therapy sessions designed to teach grammatical details in an informal, play-based format. 

Every summer our lab, in collaboration with other members of the Department of Speech, Language, and Hearing Sciences, conducts a research program for children with SLI.  Children in the program participate in both research and language therapy activities.  To learn more about our summer research program, click here Summer Fun.

The Child Language Research Laboratory team consists of faculty and staff members, postdoctoral fellows, doctoral, masters level and undergraduate students.  Laurence B. Leonard serves as Director.  Patricia Deevy is the Coordinator of our laboratory activities.

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Research Staff

Patricia Deevy

Pat earned her Ph.D. in Linguistics at the University of Massachusetts at Amherst, where her research focused on theoretical models of adult language processing.  She currently serves as full-time Research Associate and coordinates the lab activities of the Crosslinguistic project.  Her recent work deals with how on-line language processing mechanisms might interact with grammatical representations to affect language performance in children with specific language impairment. Curriculum Vitae.

Lisa Wisman Weil, M.A., CCC-SLP

Lisa received her Bachelor of Arts degree in Psychology and Communication Sciences—Disorders from Case Western Reserve University (CWRU) in 2002. She continued her studies at CWRU as an integrated graduate studies student and earned her Master of Arts degree in Communication Sciences, Disorders in 2003. While at CWRU she was mentored by Melanie Schuele and studied the acquisition of complex syntax in children with specific language impairment. Lisa worked as a pediatric speech-language pathologist for 4 years in clinic, school, and hospital settings before returning to pursue her PhD at Purdue University. Lisa’s research interests include studying child language development in typical and disordered populations as well as studying the impact of parent-child interaction and parent-focused interventions on child language development. 

Windi Krok, M.S. CCC-SLP

Windi earned her Bachelor’s degree in Psychology from the University of Michigan and her Master’s in Communication Disorders from Arizona State University. She worked clinically in the public schools and private practice for several years prior to coming to Purdue to pursue her Ph.D. Her research interests include language development in children with SLI, with a particular interest in parent-child interactions and linguistically diverse populations.

Johanna Hassink

Johanna is currently a Master's student in speech language pathology at Purdue University. For her Master's thesis she is investigating the factors that affect intervention outcomes in children with SLI. In the future, she hopes to continue her research in the area of child language as a PhD student.

In this section

• Child Language Research Lab
• Summer Fun