Anonymized sibling interaction study data for Paper 3

This record contains the anonymized, analysis-ready dataset and documentation for Paper 3 of a doctoral thesis. The dataset includes sibling play observation variables, demographic/grouping variables, engagement states, interaction quality variables, communicative initiation measures, and the attentionally matched initiation rates. Each row represents one sibling dyad/observation, and each column represents one study variable. The accompanying README describes variable definitions, coding, missing value rules, and anonymization procedures. The dataset is provided to support transparency, verification, and reproducibility of the reported analyses. Access to the data is restricted because the dataset is derived from human participant research. Requests for access will be reviewed in accordance with ethical, legal, and institutional requirements.