Proven Results: The Impact of Core5 in California

What happens when evidence-based reading instruction is implemented at scale? In a new large-scale study, Lexia's research team analyzed school-level data representing outcomes for more than 1 million California elementary students to determine the impact of Lexia® Core5® Reading on academic performance. The results are clear: schools using Core5 significantly outperformed their peers on both English Language Arts and Math Smarter Balanced assessments.

The study included 130,123 students in grades 3–5 from 525 schools that used Core5, compared against a matched sample of more than 896,000 students from 4,362 schools that did not use Core5. Even when accounting for demographics and prior achievement, schools using Core5 scored two to three points higher on the SBAC ELA assessment. These schools also observed improvements in math, showing that structured literacy instruction contributes to broader academic success.

This infographic presents key findings from the study, including criteria for sample selection, fidelity of usage, and comparative outcomes. It provides clear, actionable data for district leaders evaluating the effectiveness of their current literacy programs.

Core5's impact extends beyond reading scores. It supports foundational literacy growth that empowers students to access grade-level content across subjects. With Lexia as a trusted partner, districts can implement Core5 with confidence and see measurable gains that reflect strong instruction, consistent practice, and scalable success.