Bayley Scales of Infant and Toddler Development

The Bayley Scales of Infant and Toddler Development, third edition (Bayley-III), comprise a comprehensive developmental test for infants and toddlers from 1 to 42 months of age.

The Bayley Scales of Infant and Toddler Development are used to assess receptive and expressive language, and fine and gross motor and cognitive developmental functioning of infants and toddlers between the ages of 1 and 42 months. The test is given in the form of a series of developmentally progressive play-oriented tasks, and takes between 45 minutes and an hour to administer. Raw scores are assigned to successfully completed tasks, which then are converted to scaled and composite scores. The converted scores for the child being assessed are compared to those of a large normed group of typically developing age-sorted infants and toddlers. The Bayley-III typically is used in conjunction with an interview of the primary caregiver(s), a behavioral observation of the child, an Ages and Stages questionnaire, and a normed and validated social-emotional assessment tool.

The Bayley-III is a tool for assessing current level of developmental functioning, which is very useful in treatment planning for early intervention protocols. It provides detailed information regarding strengths and areas in need of remediation and offers a rubric for monitoring progress through progressive retesting.

The test is administered individually by having the child respond to a series of stimuli. The Mental Scales, which measure intellectual development, assess functions such as memory, learning, problem-solving ability, and verbal communication skills. The Motor Scales evaluate the child's ability to sit and stand, perform other activities requiring coordination of the large muscles (gross motor skills), and perform more delicate manipulations with fingers and hands (fine motor skills). Finally, the Infant Behavior Record (IBR) assesses the child's social and emotional development through a standardized description of the child's behavior during the testing session. Scores are measured against norms for each of the 14 different age groups. Often, the Bayley scales are used to determine whether a child is developing normally and provide for early diagnosis and intervention in cases of developmental delay, where there is significant tardiness in acquiring certain skills or performing key activities. They also can be used to qualify a child for special services and/or demonstrate the effectiveness of those services. In addition, the Bayley scales have been used to insure compliance with legislation that requires identification of at-risk children and provision of services for them.

See also Cognitive development ; Developmental delay ; Developmental psychology; Infancy .



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(MLA 8th Edition)