A Meta-Analysis of Morphological Interventions: Effects on Literacy Achievement of Children With Literacy Difficulties

Annals of Dyslexia

Goodwin, A. P., & Ahn, S. (2010).

Annals of Dyslexia, 60(2), 183-208.

This meta-analysis investigates the effects of morphological interventions on literacy outcomes in preschool- and school-aged children with literacy difficulties.

Not stated

1980-2009

Pretest-posttest control-group design studies

17

Findings demonstrated that morphological intervention were associated with improvements in literacy achievements overall (d= 0.33), phonological awareness (d= 0.49), morphological awareness (d= 0.40), vocabulary (d= 0.40) , reading comprehension (d= 0.24), and spelling (d= 0.20). No significant effect was noted for decoding, and a negative effect was noted for reading fluency (d= -0.28). Subgroup analysis yielded the following findings:<br /> <ul> <li>Morphological intervention as part of a more comprehensive instruction had a significant effect (d= 0.36), while morphological interventions in isolation had no significant effect.</li> <li>Significant effects were noted for 10 to 20 hours of instruction (d= 0.31) and 20+ hours of instructions (d= 0.32), while no significant effect was noted for 0 to 5 or 5 to 10 hours.&nbsp;</li> <li>No significant difference in outcomes were noted for individual versus group treatments.&nbsp;</li> <li>Children with speech and language delays responded most to these treatments (d= 0.77) followed by English language learners (d= 0.62), struggling readers (0.46), children with learning disabilities (d= 0.22), and children with reading disabilities (d= 0.17).&nbsp;</li> </ul>