Bayley Scales of Infant Development

Overview 

Authors: Bayley, N. & Aylaward, G.P.

Year of Publication: 2019 (4th ed)

Publisher: Pearson Assessments

Type of Assessments: 

• Standardized

• Norm-referenced

• Performanced-based

Cost: $1,498.00 (Print)/$1,313.80 (Digital)

How to Access: https://www.pearsonassessments.com/en-us/Store/Professional-Assessments/Cognition-%26-Neuro/Bayley-Scales-of-Infant-and-Toddler-Development-%7C-Fourth-Edition/p/100001996 

Age: 16 days- 42 months

Diagnoses: Children at risk for, suspected of, or diagnosed with developmental delays/disabilities (ASD, IDD, CP, language disorders, premature births, down syndrome)

Setting: Early Intervention, pediatric outpatient, NICU, preschool

Areas Assessed:

• Cognition - visual preference, attention, memory, sensorimotor, exploration & manipulation, concept formation

• Language - Receptive & Expressive

• Motor - Fine & Gross

• Social-Emotional - communicating needs, self-regulation (emotional signals)

• Adaptive Behavior - listening & understanding, talking, caring for self, relating to others, playing

Administration 

Time: 30-70 mins (depends on age of child)

Group/Individual: Individual

Subtests: 419 items spread within 5 domains 

Instructions: Examiner must determine which administration will be completed (full test, specific domains, etc). 

• The BSID is intended to be completed one-on-one so the evaluator will consult with the caregivers on the assessment process to reduce interruptions or distractions during administration. 

• The standardized script and instructions for each subtest will be followed in the item order it is listed

• The evaluator should be familiar with the instructions to ensure a more cohesive administration.

• The basal and ceiling will be determined for each subtests

• 5-minute breaks/snack is recommended if the child becomes fatigued, inattentive, or unmotivated to ensure results are accurate

Materials: Administration Manual, Technical Manual, Stimulus Book, Cognitive, Language, and Motor Record Forms, Motor-Response Booklets, Social-Emotional and Adaptive-Behavior Questionnaires, Caregiver Reports, Observational Checklist, Manipulative Set (ball puzzle, bank, bell, blocks, blue block set, bottle, buttons sleeve, car, cat puzzle, clear box, 10 coins, comb, connecting block set, 2 crayons, 2 cups, 9 disks, dog puzzle, doll, 3 ducks, ice cream cone puzzle, large ball, memory cards set A and set B, mirror, pegboard, pegs, 2 pencils, pink and blue board, rattle, red block set, ring with string, ring without string, shoelace, small ball, 2 spoons, squeeze toy, stepping path, storybook

User Qualifications: Training is available with the purchase of the complete kit, however, individuals with master's or doctorate level degrees are required.

Scoring Procedures 

How to Score: The manual may be referred to when scoring each item as each follows its own scoring criteria

• Each item will follow a 3-point scale (0,1,2). 

• At the conclusion of the administration, the behavior inventory must also be completed, tracking how many times a behavior was displayed during the session

• The caregiver will rate the frequency of the noted behaviors outside of examination on a Likert scale (never/rarely, some of the time, or most of the time)

Score Indications: 

Scoring scale: 

• 2 = Usually / Consistently

• 1 = Sometimes / Emerging

• 0 = Rarely / Not yet

• Raw scores for each subtest & domain by summing the item scores

• Utilizing the normative tables within the manual, raw scores will be converted to scaled/composite scores, percentile ranks, and age equivalents

• Lower scores may indicate developmental delays -- identify specific domains of concerns

Psychometrics

Reliability: 

• Internal consistency - High (.85-.95)

• Test-retest - High (.80-.95)

• Interrater - High (.90-.98)

Validity: 

• Demonstrates concurrent & convergent validity within a mixed-sample group when compared to the WPPSI-IV & PDMS-2

Pros & Cons

Strengths: 

• Flexibility of administration (full test, specific individual domain subtests)

• Digital version allows for improved use and accuracy

• Comprehensive assessment, reviewing multiple developmental domains

• Strong psychometrics

Weaknesses: 

• Limited age range

• Expensive & specific equipment

• Requires higher education

• Time consuming

References

• Bayley, N. & Aylward, G.P. (n.d.). Bayley scales of infant and toddler development: Fourth edition. Pearson Assessments. https://www.pearsonassessments.com/en-us/Store/Professional-Assessments/Cognition-%26-Neuro/Bayley-Scales-of-Infant-and-Toddler-Development-%7C-Fourth-Edition/p/100001996?format=KITS&tab=overview 

• Bayley, N. & Aylward, G.P. (2019). Bayley Scales of Infant and Toddler Development (4th ed.). Pearson.

• Shirley Ryan Ability Lab. (2022, August 31). Bayley scales of infant and toddler development, fourth edition. https://www.sralab.org/rehabilitation-measures/bayley-scales-infant-and-toddler-development-fourth-edition#:~:text=Unlike%20Bayley%20III%2C%20Bayley-4%20uses%20a%20polytomous%20scoring,consistent%20with%20Bayley%20III%20%28Bayley%20%26%20Aylward%2C%202019%29.