Bilingualism measures in children: A critical review of content overlap, development, and pragmatic quality.

Purpose: A variety of assessment tools (e.g. questionnaires) measure the type and degree of bilingualism in children in both research and clinical settings. Although these tools are often assumed to evaluate the same constructs and be interchangeable, this may not be the case, as indicated by other recent reviews. This review critically evaluated existing measures of child bilingualism, focusing on item-content overlap, measure development, and pragmatic quality.

Method: A database and manual search identified studies on child bilingualism measure development, which were then appraised using the Psychometric and Pragmatic Evidence Rating Scale and the Consensus-based Standards for the Selection of Health Measurement Instruments.

Result: Analysis across the six identified measures showed weak between-measure content overlap, with less than one quarter of items shared on average, suggesting they assess different constructs. Ratings indicated varied pragmatic quality, especially in assessor burden (training, interpretation). Consensus-based Standards for the Selection of Health Measurement Instruments evaluations also highlighted shortcomings in measure design and development.

Conclusion: The findings underscore the need for improved content validity and better pragmatic criteria for the clinical use of these tools. We offer recommendations for measure selection dependent on use case (e.g. setting-specific needs) and suggestions for future bilingualism measure development, prioritising a pragmatic approach.