The Research Is In: Lexia Boosts Literacy Achievement for All Learners

Figuring out whether a literacy solution will align with policymakers’ expectations and effectively meet the patchwork of instructional needs across buildings can feel like a high-pressure guessing game.

But with tight budgets and a mountain of initiatives competing for attention, district leaders can’t afford to guess. They need to act on data. 

That’s why Lexia’s science of reading-based resources—Lexia® Core5® Reading, Lexia® PowerUp Literacy®, Lexia® LETRS® Professional Learning, Lexia® Aspire Professional Learning, and Lexia English Language Development™—are not only rooted in research but also proven by it.

This post includes a roundup of key research findings, both internal and external, to show exactly how Lexia® supports students’ literacy growth. District leaders can use these findings to advocate for the implementation of Structured Literacy and make informed decisions about curriculum and professional learning investments.

The Proof Behind the Promise: Evidence of Lexia’s Impact

These research findings offer clear proof that Lexia programs deliver what they promise: Real gains in literacy achievement across grade levels and student populations.

Lexia Core5 Reading

Core5 has been rated by Evidence for ESSA for research regarding the program’s efficacy in accelerating the development of literacy skills for pre-K–5 students of all abilities. Core5 has undergone more than 10 peer-reviewed efficacy studies in the last decade, the effect sizes of which ranged from 0.06 to 0.53.

Researchers followed the progress of 1,324,201 pre-K–5 U.S. students who used Core5 during the 2023–2024 school year:

• Students working on skills at or above their grade level increased from 42% to 85% 

• Among students who were two or more grade levels behind, 40% ended the year on grade level or reached their grade-level benchmark 

• Among students who were two or more grade levels behind, 53% gained two or more grade levels in one year 

A 2023 Rand Education and Labor study evaluated the effectiveness of Core5 on 6,655 students in grades 3–5 during the 2021–2022 school year:

• Core5 students outperformed the comparison group with an effect size of 0.11

• Effect sizes favored Core5 students for each race/ethnicity subgroup—White, Black, and Hispanic students

• “High usage” Core5 students outperformed their comparison group peers with an effect size of 0.16

• Core5 students in grade 3 began the school year scoring below national MAP norms, but ended the year scoring significantly above the norms

What the Research Shows: Core5 consistently delivers accelerated academic growth, particularly for struggling readers.

Lexia PowerUp Literacy

There have been six peer-reviewed efficacy studies of PowerUp. Research into the program’s capacity to accelerate literacy gains for students in grades 6–12 at risk of not meeting College- and Career-Ready Standards has been rated by Evidence for ESSA.

Researchers followed 48,033 U.S. students in grade 6–12 who used PowerUp during the 2023–2024 school year: 

• 51% of students covered three or more grade levels of skills in a single school year 

• Students working on advanced (grade 6–8) skills across all content increased from 1% to 42%

• The number of students working on advanced comprehension skills increased 5x across the school year

A 2024 peer-reviewed study evaluated PowerUp’s effect on 26,029 Emergent Bilinguals and students struggling with literacy during the 2022–2023 school year:

• PowerUp students outperformed the control group with an average effect size of 0.14

• The Emergent Bilingual subgroup had an even larger effect size of 0.25

• Students who started PowerUp early in the school year and used it for at least an hour per week experienced higher gain scores

What the Research Shows: PowerUp significantly boosts students’ reading scores, including Emergent Bilingual learners.

Lexia English Language Development

Several studies have found K–6 Emergent Bilingual students who use the Lexia English Adaptive Blended Learning speaking and listening program outperform non-using peers on language proficiency assessments such as:

• WIDA

• California English Language Development (CA ELD)

• Texas English Language Proficiency Standards (TX ELPS)

• New York English Language Development (NY ELD)

• English Language Proficiency Assessment for the 21st Century (ELPA21)

Here’s how Emergent Bilingual students using Lexia English fared on the non-state-specific assessments, ELPA21 and WIDA, during the 2023–2024 school year.

Lexia researchers used the ELPA21 language proficiency standards to assess the progress of 19,205 students in more than 998 schools. 

• Approximately one in four students who used Lexia English as recommended moved up to the next ELPA21 proficiency band in the program

• Just more than a third (34%) of Emergent Bilingual learners who were newcomers to the country moved up a proficiency band 

Researchers also used the WIDA language proficiency standards to assess another 79,796 students in 4,108 schools.

• Approximately one in three students who used the program as recommended moved up to the next WIDA proficiency band within the program

• Just less than a third (32%) of Emergent Bilingual learners who were newcomers to the country moved up a proficiency band

What the Research Shows: Both studies comprised a total of nearly 100,000 students across more than 5,100 schools.

Professional Development (Lexia LETRS Professional Learning and Lexia Aspire Professional Learning)

The Lexia LETRS (Language Essentials for Teachers of Reading and Spelling) professional learning suite provides early childhood and elementary educators and administrators with deep knowledge in the science of reading. Lexia Aspire Professional Learning is a self-paced, digital, International Dyslexia Association® (IDA)-accredited solution that empowers educators across all content areas to accelerate literacy skills among students in grades 4–8.

More than 53% of surveyed educators believe a lack of professional development contributes to teacher burnout. More than a third (38%) strongly believe targeted professional development is crucial for their career growth. 

Across the 2023–2024 school year,

• 90% of educators who took LETRS agreed the content was relevant to their professional role and goals

• 93% of educators indicate they can apply the skills and concepts learned through LETRS to their work

• 91% of educators felt confident delivering instruction to students based on the science of reading

Among teachers who have had explicit training in reading instruction for adolescents, almost half (42%) reported an increased ability to differentiate instruction, and 36% experienced increased confidence in the classroom.

What the Research Shows: LETRS and Aspire measurably strengthen educators’ effectiveness in driving students’ literacy gains. 

Making Research-Based Decisions for Literacy Success

When decisions about literacy solutions are grounded in evidence, district leaders have a strategy for students’ lasting literacy success. Lexia's commitment to evidence-based practices and measurable achievement means district leaders can invest with confidence.

Explore the full research behind Lexia’s proven impact or connect with a Lexia expert to discuss achieving literacy goals.