The null model, including ICCs for the SDQ, for different school groups.

The null model, including ICCs for the SDQ, for different school groups.针对不同学校群组的零模型，其中包含了针对长处和困难问卷（Strengths and Difficulties Questionnaire, SDQ）的组内相关系数（Intraclass Correlation Coefficients, ICCs）。