Building Content Knowledge to Boost Comprehension in the Primary Grades

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A teal circular badge with the text “Meets Tier 1 Strong ESSA Evidence” in white, indicating a high level of evidence according to ESSA standards.

Programs:

Amplify CKLA

Recognition / Rating:

ESSA Tier 1: Strong Evidence

State:

Two large U.S. urban school districts (one mid-Atlantic, the other Southern)

Grade level:

Kindergarten

Demographics: 

  • 47 schools across two trials
  • 65 teachers
  • 1,281 students
  • Schools randomly assigned to treatment (Amplify CKLA) or business-as-usual control groups

Study years:

The study was conducted during the 2017–18 and 2018–19 school years and published in 2020.

Overview

Florida State University researchers Sonia Q. Cabell, Ph.D., and HyeJin Hwang, Ph.D., conducted two randomized controlled trials to examine whether content-rich literacy instruction could accelerate language development and content knowledge in the earliest grades. Conducted across 47 schools in large urban districts, the study assessed 1,281 kindergarten students before and after one semester of Amplify Core Knowledge Language Arts (CKLA) Knowledge instruction using both curriculum-aligned (proximal) measures and standardized assessments.

Students in the Amplify CKLA treatment group significantly outperformed the business-as-usual control group on proximal measures of vocabulary (effect size: 0.55), social studies knowledge (effect size: 0.97), and science knowledge (effect size: 0.26). The study also found a significant effect on a standardized measure of generalized vocabulary (effect size: 0.09), indicating transfer beyond the content directly taught in the curriculum.

Key takeaways

  • An independent study evaluated Amplify CKLA Knowledge instruction in kindergarten classrooms across two large urban U.S. school districts.
  • Students receiving Amplify CKLA Knowledge instruction significantly outperformed the control group on proximal measures of vocabulary (effect size: 0.63), social studies knowledge (effect size: 0.93), and science knowledge (effect size: 0.26).
  • English language learners using Amplify CKLA Knowledge instruction also significantly outperformed the control group on vocabulary (effect size: 0.40) and social studies knowledge (effect size: 0.58).
  • The study meets ESSA Tier 1: Strong Evidence, the most rigorous federal evidence standard,  based on its well-designed experimental design with random assignment and statistically significant student outcomes.
“The statistically significant impact of Amplify CKLA on standardized measures of language and science knowledge stands out because relatively few interventions actually have shown transfer to more generalized learning as measured via a standardized assessment.”

“Building Content Knowledge to Boost Comprehension in the Primary Grades”

Sonia Q. Cabell and HyeJin Hwang, 2020, Florida State University