Bayley Scales of Infant Development (BSID)

Author(s): Nancy Bayley, PhD 

Year of Publication: 2005

Publisher: Pearson

Identify Type of Assessment: Observation-based rating scale and questionnaire

Cost: 1,191.60 (For everything)

Population: Children aged 1 to 42 months

Appropriate Settings: Room large enough for assessment of gross motor skills; well lit, quiet, comfortable, and distraction free with a small table and chairs; position for each test item described.

Purpose of Assessment and Function Areas Assessed: This assess and identifies children who have delays in multiple developmental areas and provides baseline information for planning interventions. Screening test is used to determine if the child is on track developmentally or if further testing is required. 

Administration:  Time to administer: 30-90 minutes, depending on age of child; 15-25 minutes for screening test. The screening test look for cognitive, language, and motor delays to determine need for further testing. The assessment has 5 domains: (1) Cognitive (91 items): (2) Language (97 items); (3) Motor (138 items); (4) Social-Emotional (35 items based on the Social Growth Chart) and (5) Adaptive Behavior Skills (241 items). First 3 domains comprise 2 questionnaires completed by parents. Performance items are scored 0 (absence of skill) or 1 point (presence of skill); questionnaires are rated on 4- to 6- point scales on the basis of frequency of behaviors (ranging from not able to always when needed) The motor scale kit is purchased and administered separately.

User Qualifications: Typical medial professional are the only ones to use this. There is a training offered when the assessment is bought, but it is not required. 

Materials Required: The kit includes the manual, record forms, stimulus book, manipulatives, and play items. There is a optional scoring assistant and growth chart available. Screening test includes playful activities that focus on cognitive, language and motor domains. 

Scoring Procedure: The standardized mean motor score is 100. Scores lower than 85 indicate a mild impairment and lower than 70 mean moderate or severe impairment. Composite scores yield performance levels in each of the 5 areas based on cutoff scores. Caregiver report provides program and/or treatment recommendations.

Psychometrics/Standardization: Reliability- good internal consistency,  0.82-0.88.

Validity: Strong evidence of validity was based on extensive review and analysis of test content, internal structure, and relations to other variables. High concurrent validity for age equivalent scores was found only above 18 months. 

Strengths: This is a highly rated assessment from many professionals. There is a free training session that comes with the purchase of the assessment. 

Weaknesses- It is expensive and it can take a while to administer time consuming, and user qualification.