The Bayley Scales of Infant Development (BSID-III is the current version) is a standard series of measurements originally developed by psychologist Nancy Bayley used primarily to assess the motor (fine and gross), language (receptive and expressive), and cognitive development of infants and toddlers, ages 0-42 months .

This measure consists of a series of developmental play tasks.

Raw scores of successfully completed items are converted to scale scores and to composite scores.

These scores are used to determine the child’s performance compared with norms taken from typically developing children of their age (in months).

The assessment is often used in conjunction with the Social-Emotional Adaptive Behavior Questionnaire. Completed by the parent or caregiver, this questionnaire establishes the range of adaptive behaviors that the child can currently achieve and enables comparison with age norms.

What we do today makes all the difference tomorrow.

A child deserves to make his mark. Each should have every opportunity to reach his full potential .Bayley–III, is a comprehensive tool need to identify issues early on. To address early childhood situations before they become lifelong problems, and to give every child a chance to succeed.

Adaptive Behavior

Authored by ABAS®-II authors Patti L. Harrison, Ph.D. and Thomas Oakland, Ph.D.

Community use

  • Functional pre-academics
  • Home living
  • Health and safety
  • Leisure
  • Self-care
  • Self-direction
  • Social
  • Motor


  • Sensorimotor development
  • Exploration and manipulation
  • Object relatedness
  • Concept formation
  • Memory
  • Habituation
  • Visual acuity
  • Visual preference
  • Object permanence
  • Plus other aspects of cognitive processing

Items measure age-appropriate skills including:

  • Counting (with one-to-one correspondence and cardinality)
  • Visual and tactile exploration
  • Object assembly
  • Puzzle board completion
  • Matching colors
  • Comparing masses
  • Representational and pretend play
  • Discriminating patterns


assesses preverbal communications such as:

  • Babbling
  • Gesturing
  • Joint referencing
  • Turn taking
  • Vocabulary development such as naming objects, pictures, and actions
  • Morpho-syntactic development such as use of two-word utterances and use of plurals and verb tense

assesses preverbal behaviors and vocabulary development such as:

  • The ability to identify objects and pictures that are referenced
  • Vocabulary related to morphological development such as pronouns and prepositions
  • Understanding of morphological markers such as plurals and tense markings


Fine motor

Fine motor skills associated with:
  • Prehension
  • Perceptual-motor integration
  • Motor planning
  • Motor speed
Items measure age-appropriate skills including:
  • Visual tracking
  • Reaching
  • Object manipulation
  • Grasping
  • Children’s quality of movement
  • Functional hand skills
  • Responses to tactile information (sensory integration)

Gross motor

Items assess:
  • Static positioning (e.g. head control, sitting, standing)
  • Dynamic movement including locomotion (crawling, walking, running, jumping, walking up and down stairs)
  • Quality of movement (coordination when standing up, walking, kicking)
  • Balance
  • Motor planning
  • Perceptual-motor integration (e.g. imitating postures)


Developed by Stanley Greenspan, M.D., one of the world’s leading experts in child development.

  • Determines the mastery of early capacities of social-emotional growth
  • Monitors healthy social and emotional functioning
  • Monitors progress in early intervention programs
  • Detects deficits or problems with developmental social-emotional capacities
  • 0-3 months
    • Exhibits growing, self-regulation, and interest in the world
  • 4-5 months
    • Engages in relationships
  • 6-9 months
    • Uses emotions in an interactive, purposeful manner
  • 10-14 months
    • Uses a series of interactive, emotional signals or gestures to communicate
  • 15-18 months
    • Uses a series of interactive, emotional signals or gestures to solve problems
  • 19-30 months
    • Uses ideas to convey feelings, wishes, or intentions
  • 31-42 months
    • Creates logical bridges between emotions and ideas