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Bayley Scales of Infant and Toddler Development

  1. Gary J. Robertson

Published Online: 30 JAN 2010

DOI: 10.1002/9780470479216.corpsy0111

Corsini Encyclopedia of Psychology

Corsini Encyclopedia of Psychology

How to Cite

Robertson, G. J. 2010. Bayley Scales of Infant and Toddler Development. Corsini Encyclopedia of Psychology. 1–2.

Author Information

  1. Tampa, Florida

Publication History

  1. Published Online: 30 JAN 2010


The Bayley Scales are carefully constructed norm-referenced measures for assessing the development of infants and toddlers, ages 1 month to 3 years 6 months. Originally developed by Dr. Nancy Bayley and published in 1969, the Second Edition of the Bayley Scales (BSID-II) was published in 1993, and a third edition (Bayley-III) was released in 2006. The description that follows focuses on the Bayley-III, developed by the staff of the Psychological Corporation with advice from a panel of outside experts, consultants, and reviewers. The administration manual states that Bayley-III “maintains the original nature and purpose of the Bayley Scales as envisioned by its author, Nancy Bayley” (Bayley, 2006a, p.1).


  • infant development;
  • developmental assessment;
  • cognitive assessment;
  • motor assessment;
  • language assessment;
  • social-emotional assessment;
  • adaptive behavior assessment