The internal validity of observational study is often subject to debate. In this study, we define the counterfactuals as the unobserved sample and intend to quantify its relationship with the null hypothesis statistical testing (NHST). We propose the probability of a robust inference for internal validity, that is, the PIV, as a robustness index…

In this study, we explored the influence of kindergarten children's perspectives of school on their literacy and self-regulation outcomes. Children's early perspectives were captured in a three-question, finger-puppet interview. Responses to the interview questions were coded thematically as being academic and/or social in nature, and were…