Students of DG-group teachers scored significantly higher on a geometry achievement test than students of control-group teachers (p = .002), with effect size .45 and a larger effect at the Regular Geometry level¶

Claim · All claims
Evidence · 1 study · causal r2 · q3 · i1 small
Currency · newest study 2015 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i1 In a two-level HLM with pre-test, class level, and teaching experience as covariates, the DG effect on student post-test achievement was strongly significant (p = .002) with effect size .45. → Jiang et al. 2015 q3 i? The DG group outscored the control group in each level of Geometry (Regular, Pre-AP, Middle School), with the effect substantially larger at the Regular Geometry level. → Jiang et al. 2015

Evidence¶

Jiang et al. 2015¶

Zhonghong Jiang, Edwin Dickey, Alexander White, Ewelina McBroom, M. Alejandra Sorto, & Alana Rosenwasser. (2015). A Dynamic Geometry-Centered Teacher Professional Development Program and Its Impact. Proceedings of the 37th annual meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education, East Lansing, MI: Michigan State University. https://eric.ed.gov/?id=ED584322

q3 · i1 · causal · r2

Two-level hierarchical linear modeling of student Exiting Geometry Test (XGT) post-test scores with Entering Geometry Test (ENT) pre-test scores as covariate, across Regular, Pre-AP, and Middle School class levels. The article reports "the DG effect was strongly significant (p = .002)" with effect size .45.

"The results of the model indicated that the DG effect was strongly significant (p = .002). Comparing the means, the DG group was higher than the control group in each level of Geometry and the effect size (.45) was substantially larger at the Re gular Geometry level."

Discussion¶

Related Claims¶

• DG-group lessons were significantly better designed for conjecture-to-proof progression and used dynamic features far more than control lessons, while other observed teaching aspects did not differ significantly — related
• A weeklong DG-centered summer institute improved teachers' conjecturing-proving knowledge, with a statistically significant average gain of 1.37 points (p = .003) — related