Presenter: Glen P. Aylward, Ph.D., ABPP

There have been changes in the format of the Bayley Scales since the original publication in 1969. These changes include the structure of the scales, differences in overall scores, and more recently, polytomous scoring and selective use of caregiver report. These changes impact test users both in terms of contemporary diagnostics and longitudinal research application. Given that the Bayley is the international reference standard for developmental assessment in infants and toddlers ages 0-42 months, clarification of these issues is necessary. Emphasis is placed on the comparison of the Bayley-III and Bayley-4 in terms of scores, reliability, intercorrelations among scales, test duration, growth scale values, and similar topics. This presentation will be followed by a question and answer session.

Learner Outcomes

Based on the content of the webinar, participants will be able to:

1. Describe the differences and similarities between the Bayley-III and Bayley-4 in terms of statistical qualities.
2. Describe how the two versions differ clinically and apply this knowledge to developmental testing.
3. Describe the basis for changes from the Bayley-III to Bayley-4