Bayley Scales of Infant and Toddler Development®, Third Edition
Overview: Examine all the facets of a young child’s development
Age Range: 1 to 42 months
30 to 90 minutes (depending upon age of child)
Scores/Interpretation: Index scores and Subtest Scaled scores
Publication Date: 2005
What we do today makes all the difference tomorrow.
Every child deserves to make his mark. Each should have every opportunity to reach his full potential. And you can help make that possible. With Bayley–III, you have the comprehensive tool you 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. With Bayley–III, you have the power to make a positive impact, early and often.
This is your one stop location for information on the Bayley Scales of Infant and Toddler Development - Third Edition.
What’s new about Bayley-III?
Long known as the premier assessment for measuring developmental delays in the very young, this newest edition – the Bayley Scales of Infant and Toddler Development – Third Edition (Bayley–III) – combines the superior psychometric standards you expect with two additional scales and more clinically useful features than ever.
Plus . . . as a Bayley-III customer, you get unparalleled service and support from a highly credentialed sales team.
Bayley-III complete kit
Rolling case now standard!
- Social-Emotional subtest
Authored by one of the nation’s leading experts in child development, Stanley Greenspan, M.D.
- Adaptive Behavior subtest
Written by ABAS®-II authors Patti L. Harrison, Ph.D. and Thomas Oakland, Ph.D.
- Screening Test
A true screener to determine if further testing is indicated.
- Caregiver Report
With suggestions to help parents plan for their child.
- Scoring Assistant
For cognitive, language, and motor scales, adding ease and efficiency, ideal for team and arena testing.
- Growth Scores and Growth Charts
Chart a child’s growth over time.
- Easier to administer, more user-friendly. Easy-to-follow record forms, easel-back stimulus book, child-appealing manipulatives, and play-based items to facilitate assessment.
- Extended floor and ceiling. Clinician can more easily identify lower and higher functioning infants and toddlers.
- Improved clinical studies. Special data collected and presented on children with high-incidence clinical diagnoses.
- New norms. Current normative sample representing 1,700 children stratified according to age, based on the 2000 U.S. Census.
- Simplified scoring rules. It’s easier to determine if child performs target behavior.
- More parent/caregiver involvement. New test items allow for family input.
Helping children make a distinct mark through better assessment in all five IDEA areas.
Even when a child can’t speak, he can tell us something. How he feels. How he thinks. How he interacts with the world around him. And we need to know how to read the signs. With Bayley-III, you can. You have a comprehensive tool for identifying, measuring, and assessing a child’s development.
For over 20 years, professionals working with infants and toddlers have relied on the proven Bayley Scales of Infant Development. And today, they have even greater reason to do so. With the new Bayley–III, professionals have the most comprehensive assessment tool for determining developmental delays in children one month to 42 months old.
Bayley-III Complete Test
Easy to Use.
Hard to argue with.
Unlike other solutions that have manipulatives that can be cumbersome or time consuming, Bayley–III is easy to use and to transport. It’s also very easy to administer, and the results are exceedingly reliable. It is administered using a caregiver’s or parent’s involvement, allowing more input to be gathered from the child’s natural environment. Additionally, all assessment factors are based on the age of the child, allowing for more accurate developmental assessments.
Rolling case for easier portability
Who can use Bayley–III?
You must have the ability, not just to administer the test, but to analyze and interpret the results. Qualified personnel will likely have training in the following areas:
- formal training in the use, administration and interpretation of standardized assessment tools and psychometrics
- supervised mental health and/or educational training specific to working with parents and assessing young children
- supervised training in infant and child development
Sample qualified personnel: psychologists, psychiatrists, speech and language therapists, occupational and physical therapists specializing in early intervention, early interventionists, social workers, developmental pediatricians, pediatric nurse practitioners. Those who qualify will most likely have at least a Master’s degree.
If you are an appropriately trained, experienced practitioner in these areas, you can benefit from using Bayley–III.
- Early intervention specialist
- Early childhood specialist
- Childhood development specialist
- Cross-disciplinary professional
- School psychologist
- Assessment specialist
Features & Benefits
- Core battery of five scales.
- Three scales administered with child interaction – cognitive, motor, language.
- Two scales conducted with parent questionnaires – social-emotional, adaptive behavior.
- Ideal for team-testing or multi-disciplinary teams where a professional in each area may assess the child (psychologist, SLP, OT/PT).
- Caregiver Report Form – a template for the examiner to provide scores, information on tests given, how the child performed and recommendations.
- Behavior Observation Inventory – separate scale for validating examiner and parent perceptions of the child’s responses.
- Extensive clinical studies – including premature, small for gestational age, Downs syndrome, pervasive developmental disorder, at-risk, FAS/poly substance use, asphyxia, cerebral palsy and language impairment.
- Extensive validity studies –
- Bayley Scales of Infant Development – Second Edition.
- Preschool Language Scale – Fourth Edition.
- Adaptive Behavior Assessment System®– Second Edition.
- Wechsler Preschool and Primary Scale of Intelligence™ – Third Edition.
- Infant-Toddler Social Emotional Assessment.
- Peabody Developmental Motor Scales – Second Edition.
- Reduced kit weight and size.
- Simplified scoring rules.
- Rolling case portability for easier travel.
- Easier to determine if child performed the target behavior.
- Playful, engaging toys and activities
- Excellent validity and reliability
- Scores provided: standard scores, age equivalents, percentiles, with cut scores and T scores.
- Optional training materials available
- Scoring Assistant - optional
- Ideal for use when you suspect delays or problems in early development
- Determines the need for further in-depth assessment
- Indicates strengths, weaknesses, and competencies so that parents and professionals can properly plan for the child
- Aligns with IDEA requirements for support and intervention
- Excellent for use in cross-disciplinary teams
- Allows for more caregiver involvement in test items
Helping you link assessment with intervention.
- Identifies infant and toddler strengths and competencies, as well as their weaknesses.
- Provides normative information consistent with developmental domains identified by current IDEA early childhood legislation.
- Valid and reliable measure of a child’s abilities.
- Comparison data for children with high-incidence clinical diagnoses.
- Flexible – can administer one or more domain subtests individually.
- Growth scores can be used to chart intervention progress.
Areas of Assessment
Bayley-III: The Definitive Solution
The definitive solution for measuring the complete child.
Bayley-III Developmental Domains
Five Developmental Domains
Table of Contents of Developmental Domains
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
- Sensorimotor development
- Exploration and manipulation
- Object relatedness
- Concept formation
- 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:
- 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 skills associated with:
- Perceptual-motor integration
- Motor planning
- Motor speed
Items measure age-appropriate skills including:
- Visual tracking
- Object manipulation
- Children’s quality of movement
- Functional hand skills
- Responses to tactile information (sensory integration)
- 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)
- Motor planning
- Perceptual-motor integration (e.g. imitating postures)
- 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
Bayley–III™ Scoring Assistant® or Hand Scoring
You can hand-score the assessment or use the Scoring Assistant software for quick and accurate reporting.
- Bayley-III SA Parent Sample Report (PDF - 53kb)
- Bayley-III SA Parent Sample Report Part 2 (PDF - 196kb)
Windows 7, XP, or Vista
Bayley-III Observational Checklist
Lists nearly 100 items that can be easily observed at any time during administration. Use the checklist to familiarize yourself with those items that can be observed outside the standard administration order, saving precious administration time. Make paper copies or use a grease pencil to note observed items, then later transfer to the master record form or input to the Scoring Assistant.
Training Assistance– You choose the format!
Training on the new Bayley–III instrument is available in many forms to meet your needs:
- Fundamental Administration (DVD)
- Enhanced Administration/Scoring Resource (DVD)
- On-site workshops
Bayley-III On-site Workshops
Contact us for information on hosting or attending.
Learn how the new Bayley complete battery addresses all five IDEA areas and is easier and better than ever!
- Ideal for psychologists, early interventionists, early childhood specialists.
- Learn what's new and improved in the new edition - addresses all five IDEA areas.
- Learn easier scoring and interpretive procedures.
- Understand composition and uses of subtests.
- Screening Test also available.
Introducing the Bayley-III
This pre-recorded 20-30 minute session allows you to learn at your leisure. All you need is access to the Internet and the sound enabled on your computer. Please keep in mind that the session may take a few minutes to load.
Learn about the test that helps you screen for developmental delays and then conduct in-depth assessment, if needed.
Bayley-III: Administration and Scoring
Presenter: Dr. Gloria Maccow
The Bayley Scales of Infant and Toddler Development-Third Edition is an individually administered test designed to assess developmental functioning of infants and toddlers. The Bayley-III assesses development in five areas: cognitive, language, motor, social-emotional, and adaptive behavior. During this three-hour webinar, the presenter will describe administration, scoring, and interpretation of the Bayley-III components.
This web-based presentation will:
- Describe the administration and scoring of items on the Cognitive, Language, and Motor domains
- Discuss completion of the Social-Emotional and Adaptive Behavior Questionnaire
- Describe how to convert raw scores to standardized scores
- Discuss interpretation of the results
Our presenter, Gloria Maccow, PhD, is an Assessment Training Consultant with Pearson. She was trained as a school psychologist at Texas A&M University and at the University of Florida. She worked for two years as Supervisor of Psychological Services and for several years as a school psychologist with Guilford County Schools in North Carolina. She provided training for graduate students in school psychology at Indiana State University and at Illinois State University, and she worked as a psychologist in private practice in Greensboro, NC.
Date: Apr 26, 2011
Frequently asked questions follow. Click on a question to see the response.
How much overlap is there between the Preschool Language Scale—Fourth Edition and the Bayley–III Language Scale?
There are only 44 items in the Bayley–III Language Scale that originated from the PLS-4. A validity study between the PLS–4 and the Bayley–III indicate no practice effects between the two tests, so administration of one test does not affect performance on the other test.
Where can I find additional interpretive guidelines for the Social-Emotional Scale?
For additional interpretive guidelines specific to the social-emotional score, Dr. Greenspan includes some "next steps" within the manual for the Greenspan Social-Emotional Growth Chart. The material is adapted from what is found in books authored by Dr. Greenspan (including Building Healthy Minds and The Functional Emotional Assessment Scale for Infancy and Early Childhood).
Can all items that use the same materials within an age group be administered one after the other (e.g., all items that use blocks), similar to the BSID–II administration format?
Because the items are ordered by difficulty, administer the items in each subtest in the order listed (with the exception of series items). The subtests were standardized by having examiners follow the item order provided. It also ensures that all pertinent items are administered (none are forgotten), and that reversal and discontinue rules are met quickly, with no extraneous items that may contribute to the fatigue of the child.
There is an item on the Bayley–III video that shows the examiner positioned across from the child, when the Administration Manual indicates that for the item, the examiner should be positioned next to the child. Which directions should I follow?
The item in question is "Uses pencil to obtain object." The examiner should position him- or herself alongside the child, to give the child the proper perspective. In all instances, the directions in the Administration Manual should be followed.
Why is it recommended to administer the Receptive Communication subtest prior to the Expressive Communication subtest?
Statistically, we did not find practice effects based on subtest order for any subtests. The number of items that can be scored through observation of the child also minimizes the likelihood of practice effects with the Communication subtests. However, there are some reasons for recommending that Receptive Communication be administered prior to Expressive Communication. Some stimulus items are similar across content and repeated exposure to these pictures may make it easier for the child to recognize them in the Receptive Communication subtest. In addition, many young children must establish rapport with the examiner before expressing themselves vocally by naming objects or speaking to the examiner; the Receptive items can help familiarize the child with tasks and encourage vocalizations.
There are a number of items that can be considered sequential that either are not marked as sequential, or are only partially noted as sequential (i.e., later items in the “sequence” not listed). Why aren’t these noted as series items?
Items are marked as series items only if the administration is exactly the same for each item in the series. That is why the Rotated Pink Board is not identified as part of the Pink Board Series.
How soon can the Bayley–III be readministered in order to measure growth?
The types of items administered to infants are unlikely to be "learned" or to produce practice effects, so children can be readministered the Bayley–III in a shorter time frame. An interval of approximately 3 months is recommended for children under 12 months of age; an interval of approximately 6 months is recommended for children older than 12 months, although shorter intervals can be used if warranted.
What start point should an examiner use when testing a child with suspected deficits?
The start points were chosen to accommodate most children with some degree of delay. If the examiner suspects sufficient delays such that the child will likely reverse, the examiner can begin one start point below the age-appropriate start point, and reverse as needed. It is not recommended that the examiner begin administration any earlier, in order to eliminate the possibility of multiple basals.
Is the Language Scale sufficiently comprehensive so that additional language assessment is not necessary, especially for the younger children?
The Language Scale is sufficient for determining if a language problem exists. It may also indicate what language problem it is likely to be. However, in order to pinpoint the problem to determine appropriate intervention (particularly if referring to a Speech Language Pathologist), additional assessment will be necessary. The Preschool Language Scale—Fourth Edition is one instrument that can be given if the Bayley–III Language Scale indicates delays.
What was the rationale for adjusting prematurity up to 24 months?
It was a combination of evidence from the literature and recommendations from the Bayley–III advisory panel. Discussions for adjusting to prematurity to 24 months of age began early in the development process of the Bayley–III and follows the same recommendations made for the BSID–II. The adjustment for prematurity was not taken beyond 24 months because the advisory panel and the literature indicate the vast majority of children "catch up" by 24 months of age.
Can children be administered the Bayley–III in the home setting?
The Bayley-III CAN be administered in the home, but the examiner must maintain standard procedures and keep distractions to a minimum.
For children ages 2:6–3:6, both the Bayley–III and the Wechsler Preschool and Primary Scale of Intelligence—Third Edition (WPPSI–III; Wechsler, 2002) could be administered. Which instrument should be used for this age range?
Which test to use depends on your clinical judgment and the purpose of testing. Practitioners can use either or both instruments for children ages 30–42 months (2 years 6 months and 3 years 6 months). Though both measures provide an estimate of a child’s cognitive functioning, the instruments are designed for different purposes. The Bayley–III provides information about whether a child’s developmental trajectory in the cognitive domain is proceeding as expected, relative to same-age peers. It also provides this type of information for language, motor, social-emotional, and adaptive behavior domains. The WPPSI–III is specifically designed to measure a child’s overall cognitive ability, as well as his or her cognitive ability in more specific domains (e.g., verbal, perceptual, processing speed). The Bayley–III should be used to evaluate cognitive ability in low-functioning children in this age range because it provides an extended floor. The WPPSI–III should be used to evaluate cognitive ability in high-functioning children in this age range, because it provides an extended ceiling. If results of the Bayley–III suggest delays in the cognitive domain, the WPPSI–III may provide additional information on the specific areas of cognitive ability that are problematic for the child. If an ability score (e.g., FSIQ) is required, the WPPSI–III should be used.
Will there be Cognitive-Language Composite score similar to the BSID–II MDI? Is there an overall score available?
At this point, there are no plans to develop either a Bayley-III Cognitive-Language composite score that corresponds with the BSID-II MDI or an overall composite. The reasoning behind separating the scores is because at this young age it is important to distinguish between delays related to language difficulty and those related to cognitive difficulty. U.S. federal mandates, such as IDEIA, emphasize the need to provide scores for the individual domains, rather than a global composite score. A composite score can also mask delays if one area is strong while the other is weak.
If the Social-Emotional Scale on the Bayley–III is the same as the Greenspan Social-Emotional Growth Chart, why are there different scores available for the two instruments?
The difference between the Greenspan Social-Emotional Growth Chart and the Bayley–III Social-Emotional Scale is that the Greenspan Social-Emotional Growth Chart provides only cut scores; the Bayley-III provides scaled scores for this measure.
Can an examiner accept baby signs/ASL as words on the Expressive Communication Scale?
Many of the Expressive Communication items indicate that approximations (the implication being verbal approximations) can be accepted. If the child is capable of speaking, the child should be prompted to use spoken words rather than signs. If, however, the child is signing as an accommodation, then the clinician would need to take that into account when interpreting the results.
What is the difference between a score of 0 (can’t tell) and 1 (none of the time) for the Social-Emotional Scale?
The score of 0 should be chosen if the respondent doesn't feel he/she knows the child well enough to respond with confidence (lack of familiarity with the child or limited settings in which the respondent has observed the child). The score of 1 should be chosen if the respondent is familiar enough with the child to know that the child never exhibits those behaviors.
Why are there separate Record Forms for each of the Cognitive, Language, and Motor Scales? Are they different from what is contained in the comprehensive Record Form?
A separate Record Form is available for each Scale in order to provide flexibility for customer needs. For instance, these record forms can provide more efficiency when conducting research, and for multidisciplinary and arena assessment teams. The standard Record Form (combining all 3 Scales) contains all the information and items found in the individual Record Forms.