Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

PURPOSE: In this article, the authors present a tutorial on the use of developmental trajectories for studying language and cognitive impairments in developmental disorders and compare this method with the use of matching. METHOD: The authors assess the strengths, limitations, and practical implications of each method. The contrast between the methodologies is highlighted using the example of developmental delay and the criteria used to distinguish delay from atypical development. RESULTS: The authors argue for the utility of the trajectory approach, using illustrations from studies investigating language and cognitive impairments in individuals with Williams syndrome, Down syndrome, and autism spectrum disorder. CONCLUSION: Two conclusions were reached: (a) An understanding of the underlying mechanism will be furthered by the richer descriptive vocabulary provided by the trajectories approach (e.g., in distinguishing different types of delay) and (b) an optimal design for studying developmental disorders is to combine initial cross-sectional designs with longitudinal follow-up.

Original publication

DOI

10.1044/1092-4388(2009/07-0144)

Type

Journal article

Journal

J Speech Lang Hear Res

Publication Date

04/2009

Volume

52

Pages

336 - 358

Keywords

Child, Child Development, Child, Preschool, Cognition Disorders, Cross-Sectional Studies, Developmental Disabilities, Down Syndrome, Humans, Language Disorders, Longitudinal Studies, Memory Disorders, Williams Syndrome