Abstract
Approximately 25% of adults in the United States aged 16 and older have difficulty with basic reading skills, yet research on effective interventions for this population remains limited. This systematic review synthesizes evidence on reading component interventions for adult literacy learners published between 2010 and 2025, addressing three questions:
- What student and intervention characteristics have been examined?
- Which reading components have been targeted?
- What does research indicate about intervention effectiveness?
Following a systematic search across eight databases, 15 peer-reviewed studies met all inclusion criteria. Participants were adults aged 16–76 enrolled in Adult Basic and Secondary Education programs, correctional education, and postsecondary transitional programs, primarily in the United States. Findings indicate that adult literacy interventions most consistently improved decoding skills, with small to moderate effect sizes, particularly on untimed assessments. Fluency results were generally positive but mixed. Evidence for vocabulary, spelling, morphological skills, and phonological skills was limited by infrequent assessment and inconsistent findings. Reading comprehension results varied considerably by assessment type, with some larger RCTs showing small to moderate gains. Key methodological challenges included high attrition, variable intervention dosage, and inconsistent fidelity reporting. Future research should prioritize underexamined reading components, stronger research designs, and greater attention to professional development for adult literacy instructors.
