The Bayley Scales measure the mental and motor development and test behavior of infants from one to forty-two months of age. The Scales may be used to describe the current developmental functioning of infants and to assist in diagnosis and treatment planning for infants with developmental delays or disabilities. In order to use them properly, professionals need an authoritative source of advice and guidance on how to administer, score, and interpret these tests.

The initial chapters of Essentials of Bayley Scales of Infant Development II Assessment provide step-by-step instruction on test administration, scoring, and interpretation. In the following chapters, the authors provide expert assessment of the relative strengths and weaknesses of the Bayley Scales, valuable advice on their clinical applications, and several illuminating case reports.