Supporting Data for “The Effectiveness of a School-Based Book Reading Intervention for Young Dai–Mandarin

Each child was assigned a coded case number so that assessment scores could be linked across testing points and, where applicable, matched with parental questionnaire responses while protecting participant confidentiality.</p><p dir="ltr">The deposit contains the data supporting Chapters 2–5 of the thesis. Chapter 2 includes supporting data for a systematic review and meta-analysis, including records of studies excluded following full-text review, coded study characteristics, methodological-quality assessments, and extracted pretest and posttest summary statistics used in the quantitative synthesis.

Chapter 3 contains participant-level language-assessment data, home-language-environment data, socioeconomic-status questionnaire responses, and treatment-group gain scores. The language, socioeconomic-status questionnaire, and home-language-environment datasets contain records for 51 children; and the treatment-group gain-score dataset contains records for 26 children. Chapter 4 contains longitudinal Mandarin language-assessment data for 338 children in the treatment and control groups.

Each child has one Time 1 pretest record and one Time 2 posttest record, resulting in 676 child-time observations. Chapter 5 contains four longitudinal datasets covering Mandarin and Dai narrative assessments. Each Chapter 5 dataset likewise contains 338 children and 676 pretest and posttest observations.

The Chapter 5 data include narrative comprehension, story structure, structural complexity, internal-state terms, vocabulary, output language, and language-experience measures.</p><p dir="ltr">The measures represented in the deposited data include the Chinese Language Assessment Scales-Receptive (CLAS-R), Chinese Language Assessment Scales-Expressive (CLAS-E), Liwa Language Assessment-Receptive (LLA-R), Liwa Language Assessment-Expressive (LLA-E), Curriculum-Based Vocabulary Test-Receptive (CBVT-R), Curriculum-Based Vocabulary Test-Expressive (CBVT-E), Peabody Picture Vocabulary Test (PPVT), Expressive Vocabulary Test (EVT), Multilingual Assessment Instrument for Narratives (MAIN), and Researcher-Developed Vocabulary Test (RDVT).

Additional measures cover children’s home language exposure and use, socioeconomic background, verbal short-term memory, Mandarin and Dai narrative skills, and language choice during narrative tasks.</p><p dir="ltr">The deposited spreadsheets are cleaned, analysis-ready versions of the research data. Variable names have been standardized for clarity and consistency. Missing, unavailable, or non-applicable observations are left blank, and no missing values have been statistically imputed in the deposited files.

The accompanying README.txt explains the organization and contents of the deposit, and CODEBOOK.xlsx provides variable definitions, abbreviations, measurement information, categorical-value labels, and scoring notes.</p><p dir="ltr">The empirical research involving children was reviewed and approved by the Human Research Ethics Committee (HREC) of the University of Hong Kong (Reference No. EA230323). Written informed consent was obtained from the children’s parents or legal guardians, kindergarten principals, and participating teachers.

The participating children provided oral assent in accordance with the approved research procedures.</p><p dir="ltr">Direct personal identifiers, including participants’ names and contact details, have been removed from the deposited files. Children, classes, and schools are represented by coded identifiers.</p><p dir="ltr">Further information about participant recruitment, intervention procedures, assessment administration, scoring procedures, and statistical analyses is provided in the corresponding chapters of the thesis.</p>