The University of Iowa

A Synthesis of Morphology Interventions and Effects on Reading Outcomes for Students in Grades K-12


This article synthesized the morphology intervention studies conducted in English with students in kindergarten through 12th grade between 1986 and 2006. Seven studies were identified as focusing primarily on morphology instruction, including roots and affixes, and measuring one or more reading-related outcomes (e.g., word identification, spelling, vocabulary, reading comprehension). Of those studies meeting the criteria, three studies were focused on word identification, three were focused on vocabulary acquisition, and one was focused on spelling. Although there was a wide range in effect sizes computed for the various outcome measures (−.93 to 9.13), findings indicated that stronger effects were associated with root word instruction (as opposed to affixes alone) and with morphology instruction that targeted students' reading developmental level in an age of acquisition pattern. In addition, results suggested that morphology could successfully be combined with training in other skills without adding instructional time.


Reed, D. K. (2008). A synthesis of morphology interventions and effects on reading outcomes for students in grades K-12. Learning Disability Research & Practice, 23(1), 36-49. doi: 10.1111/j.1540-5826.2007.00261.v

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