7/14/2023

Lexia® LETRS® Efficacy Research

Language Essentials for Teachers of Reading and Spelling, 3rd Edition (LETRS®) teaches educators the skills needed to master the fundamentals of reading instruction — phonological awareness, phonics, fluency, vocabulary, comprehension, writing, and language. Educators who complete LETRS gain the deep knowledge needed to be literacy and language experts in the science of reading.

Lexia is dedicated to conducting rigorous scientific research to demonstrate the efficacy of its programs. This document summarizes 18 research studies that provide an evidence base establishing the efficacy of LETRS. Included are two peer-reviewed publications, 12 doctoral dissertations and four evaluations conducted by external researchers. Of these studies, one meets the second highest tier of evidence for an educational intervention described by the Every Student Succeeds Act (ESSA).

The studies summarized in this report provide an evidence base establishing the efficacy of LETRS. Studies on LETRS 1st and 2nd Editions are included – together with more recent studies on LETRS 3rd Edition. Studies on earlier editions demonstrate a rationale that LETRS 3rd Edition would be effective for teachers and students. Though research on LETRS 3rd Edition is limited, the weight of empirical evidence suggests it can improve teacher knowledge and instruction when used as intended. Download a copy for detailed information about each study, including a link to the original publication.