Bayley-4 UK is the most comprehensive assessment tool for determining developmental delays in children.      
Bayley 4 Kit
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Bayley Scales of Infant and Toddler Development | Fourth Edition

Bayley-4 UK

Bayley-4 UK is the most comprehensive assessment tool for determining developmental delays in children.      
View all tests and materials

Practical Applications of the Bayley-4 On-demand

A103000323407

Qualification Level

B
This interactive learning track with Dr Betty Hutchon DSc MRCOT, Honorary Consultant Neurodevelopmental Occupational Therapist at University College London Hospital (UCLH) covers practical considerations for administering and interpreting the Bayley-4 in clinical practice, using both clinical and typically developing video case studies. Participants will have access to this course for one year.
£281.40
Publication date:
2023
Age range:
16 days to 42 months
Scores/Interpretation:
Subtest level scaled scores, domain level composite scores, percentile ranks, confidence intervals, developmental age equivalents, and growth scale values 
Qualification level:
B
Completion time:
30 to 70 minutes (depending upon age of child)
Administration:
Paper-and-pencil; Q-global
Scoring options:
Q-global (web-based); Manual
 

Bayley-4: Enhancing Developmental Assessment in Neonatal Medicine

Curious to learn more about how Bayley-4 is helping organisations like UCLH make a bigger impact? Read the full success story and discover the powerful benefits of the latest Bayley assessment.

Read the story

Professionals have relied on the Bayley Scales of Infant and Toddler Development™ for more than 50 years to identify potential delays in children and get interventions in place early on. 

Benefits

  • Use caregiver responses to support the scoring of certain items.
  • Determine the need for further in-depth assessment.
  • Administer one or more domain subtests individually.
  • Save significant time through shortened adaptive behaviour content from Vineland 3.

Features

The new version of the Bayley Scales of Infant and Toddler Development Fourth Edition features:

  • The digital delivery option via Q-global combines the record form and administration manual, which allows greater flexibility, ease of use, and improved accuracy.
  • Content updates are made based on research and user feedback.
  • Updated normative data and clinical studies.

Five developmental domains

 

 

 

Bayley-4 UK Training Offerings

Visit our Bayley-4 UK training page to find the training that suits your needs including our scheduled 2-day online workshop. Upcoming dates and booking information can be found here.

Our interactive two-day online workshop will teach course participants to administer, score and interpret the Bayley-4, using videos of young children with and without clinical presentations. Participants will learn how to administer and score the Cognitive, Language and Motor scales.

Unsure about which Bayley-4 UK training is best for you? Download our Training Offering & Decision Tree PDF to compare the range of options available.

To purchase, select the training tile above this tab to complete your order online.

Bayley-4 UK March 2026

Join Dr. Betty Hutchon for an introductory two-day workshop to learn Bayley-4 UK administration, and scoring. Includes video case studies and interactive discussion to enhance your expertise.

 

Kits, components, and pricing

Materials are available to purchase separately; however, it is more expensive to upgrade this way than to purchase a new kit, i.e. the items required to upgrade would be:

  • Bayley-4 UK Administration Manual (paper or digital)
  • Bayley-4 UK Technical Manual (paper or digital)
  • Bayley-4 UK Stimulus Book (paper)
  • New Manipulatives (small set of discs (3); cat puzzle; memory cards; ducks; coins bank; large discs (6); small car)
  • For manual administration and scoring:
    • Bayley-4 UK Record Forms and Response Booklets (pkg of 25 of each)
    • Social-Emotional and Adaptive Behaviour Questionnaires (pkg 25)
    • Caregiver Report (pkg of 25)
  • For digital administration and scoring:
    • Q-global: Cognitive, Language and Motor administration, scoring & report and Response Booklets
    • Q-global: Social-Emotional & Adaptive Behaviour administration, scoring and report

The Scoring Subscriptions provide a digital scoring option for paper-based administration. They allow manual entry of raw data to generate scores and reports.

The Cognitive, Language and Motor Administration, Scoring and Report is used for the on-screen administration of these domains, and is a digital version of the Record Form. This is for the Examiner to use and complete.

The Social-Emotional and Adaptive Behaviour Administration, Scoring and Report is a digital equivalent of the Social-Emotional & Adaptive Behaviour Questionnaire. This is a caregiver questionnaire that can be emailed to the caregiver with a secure link to complete or can be completed within your office on an internet-enabled device.

Pearson provides product credit on qualifying returns. Find out more at here.

We anticipate that Bayley-4 UK will ship Summer 2023.

Content

For certain questions a caregiver response is possible for scoring the item, see the example below:

Ask the caregiver, 'When you say the name of a familiar object, does [insert child's name] look at the object you named often, not often, or not at all?'

Score
2 points, Often
1 point, Not often
0 points, Not at all

The Caregiver Question should not be used in every item where it is an option or where a score of '2' is not assigned. The intent of the caregiver questions is not to optimise scores as much as possible. Rather, they are to be used when a response is ambiguous, the child is not cooperative, or if the behaviour may have a greater likelihood of occurring in familiar surroundings. Frequent discrepancies between what is observed during testing and the caregiver question responses raises questions regarding the validity of Caregiver Question scores, and clinical judgement should guide interpretation.  

Prematurity is considered 36 weeks 6 days or less gestation. This is what is meant by '36 weeks or less gestation' on page 27 of the Bayley-4 UK administration manual.

Digital Administration and Scoring

This is possible and depends on how the account is set up. Some Q-global users intentionally set up their accounts so that all their team members can view their examinees as a group (rather than just the ones they have entered). Of course, an account can also be set up so that users can only see their own examinees. This is a choice made when the account is set up.

If an account is set up so that it is in the same hierarchy as other accounts, then the examinee record can be moved from one account to another for other disciplines to enter and score their section. Examinee records cannot be moved to an account within a separate entity / hierarchy.

The digital administration of Bayley-4 UK is a digital record form, the child does not interact with the administration device (e.g. tablet/laptop), the administration guidelines between paper and digital are the same.

As part of the Bayley-4 UK validation we conducted a study comparing performance on Bayley-III UK (paper scoring) and Bayley-4 UK (digital scoring). The data indicates that the children's performance on the two tests are similar (no significant difference).

The digital administration uses Q-global and combines the record form and administration manual for more streamlined administration. It is optimised for the screen-size of a tablet (e.g. iPad) or larger. Although it will work on a smart phone it will not be a good user experience. Q-global can be used on any device that has internet. You cannot use Q-global without internet access.

The Social-Emotional and Adaptive Behaviour Questionnaires can be administered remotely via a secure email link.

It is recommended to adjust for prematurity up to 24 chronological months, however, the platform will allow you to adjust beyond this age. There is on-screen text advising the recommended ages for adjusting.

Growth Scale Values are included in Bayley-4 UK. These are useful for re-evaluation purposes and are available for both paper and digital administration.

For paper administration statistical significance is also available to evaluate change in Growth Score Values between two administrations.

Information is continually backed up in Q-global, if so a connection drops during administration then any data entered will have been saved. Once you're able to reconnect, the session will continue from where you left off.
Offline administration is not available currently. The back-up option is to use paper administration, and enter the scores manually; a subscription version of Bayley-4 UK on Q-global is available to facilitate this.
The Social-Emotional and Adaptive Behaviour Questionnaire can be administered remotely. Guidance to support telepractice administration of Bayley-4 UK  is available here.

Psychometrics 

Growth scale values (GSVs) provide a score metric that does not involve age-based comparisons. Their purpose is for tracking performance across repeated test administrations. If a raw score increases upon a repeat administration, the GSV also increases.

The GSVs have a mean of 500 and a SD of 25. Because of their construction, GSVs cannot be meaningfully compared between subtests or subdomains. GSVs enable the measurement of an individual child's progress or improvement in an absolute sense. Although the normative scaled scores provide information about a child relative to their peers at a given time and may show little change over time, the GSV can provide an ability to estimate independent of one's peers and can track growth over time.

Training 

If you purchased our Bayley-4 UK Complete Kit (Print) / On-demand Training Combo or Bayley-4 UK Complete Kit (Digital) / On-demand Training, please refer to the welcome letter provided with your kit.

If you have not purchased one of our bundled options (kit + training), you can view training options under the training tab on the Bayley-4 UK webpage.

 
The following training events are available for Bayley-4 

Introduction to Bayley-4 UK Webinar (Recording)
Presenter(s): Melinda Cooper

Bayley-4 UK is the most comprehensive assessment tool for determining developmental delays in children. In this presentation Melinda Cooper, Senior Product Manager, Occupational Therapy will cover:

  • An introduction to the Bayley-4 UK
  • Revision goals
  • What has changed from Bayley-III
  • New administration and scoring features
  • What else is coming soon

Evaluating Language Skills and Early Signs of ASD with the Bayley-4  Webinar (Recording)
Presenter(s): Anise Flowers & Shannon Wang

One of the diagnostic areas that characterise Autism Spectrum Disorder is impaired communication. The Bayley-4 can be used to evaluate the early communication skills of children aged 16 days to 42 months. The presenters will describe Bayley-4's flexible administration process, which includes series items, related items, caregiver questions, and digital administration.

Recorded: Tuesday, 16th March, 2021

 
Considerations in Conducting Developmental Assessments Using the Bayley-4 Webinar (Recording)
Presenter(s): Gloria Maccow, Ph.D

Using multiple methods and collecting information from multiple sources are considered best practices when assessing infants and toddlers to identify developmental delays. When the assessment includes standardised tests, it is important to consider how the early development and behaviours of young children can impact their performance, especially on structured tasks.

Recorded: Thursday, 22nd October, 2020