Context: A perennial problem in applied statistics is the inability to justify strong claims about cause-and-effect relationships without full knowledge of the mechanism determining selection into treatment. Few research designs other than the well-implemented random assignment study meet this requirement. Researchers have proposed partial…

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…

This study investigates the effectiveness of a modified flipped classroom that integrated with a technology-enhanced Predict-Observe-Explain strategy to improve students' self-regulated learning abilities, learning performance and science process skills in a secondary school in Hong Kong. An experimental group of modified flipped classroom (n =…

The benefits of technological and theoretical scaffolding were observed when pre-service teachers aiming to teach upper elementary grades were given three learning-based geometrical inquiry tasks involving inscribed circles. They were asked to collaboratively examine the accompanying geometrical illustration and data for some new or interesting…

Programs that improve teaching effectiveness represent a core strategy to improve student educational outcomes and close student achievement gaps. This article compiles empirical values of intraclass correlations for designing effective and efficient experimental studies evaluating the effects of these programs. The Early Childhood Longitudinal…

Most grading done at high schools in the United States results in a single grade for a single class on a report card or transcript. A single number or letter lacks context and cannot effectively communicate a student's proficiency in content or skills. Altering or expanding a school's grading scheme may originate at the district or school level,…