Effects of a Structured Decoding Curriculum on Adult Literacy Learners' Reading Development

This article reports the results from a randomized control field trial that investigated the impact of an enhanced decoding and spelling curriculum on the development of adult basic education (ABE) learners' reading skills. Sixteen ABE programs that offered class-based instruction to Low-Intermediate-level learners were randomly assigned to either the treatment group or the control group. Reading instructors in the 8 treatment programs taught decoding and spelling using the study-developed curriculum, Making Sense of Decoding and Spelling, and instructors in the 8 control programs used their existing reading instruction. A comparison group of 7 ABE programs whose instructors used K-3 structured curricula adapted for use with ABE learners were included for supplemental analyses. Seventy-one reading classes, 34 instructors, and 349 adult learners with pre- and posttests participated in the study. The study found significantly greater gains for the treatment group relative to the control group on one measure of decoding skills, which was the proximal target of the curriculum. No treatment-control differences were found for gains on word recognition, spelling, fluency, or comprehension. Pretest-to-posttest gains for word recognition and spelling were small to moderate but not significantly better than the control classes. Adult learners who were born and educated outside of the United States made larger gains on 7 of the 11 reading measures than learners who were born and educated within the United States. However, participation in the treatment curriculum was more beneficial for learners who were born and educated in the United States in developing their word recognition skills.