Learning Disabilities Research & Practice, 18(4), 255–267 Copyright C  2003, The Division for Learning Disabilities of the Council for Exceptional Children Learner Characteristics that Influence the Treatment Effectiveness of Early Literacy Interventions: A Meta-Analytic Review J. Ron Nelson, Gregory J. Benner, and Jorge Gonzalez Center for At-Risk Children’s Services, University of Nebraska–Lincoln The purpose of this article was to systematically review the available research on learner charac- teristics that influence the treatment effectiveness of early literacy interventions. Meta-analytic procedures were applied to a total of 30 studies that met the inclusionary and exclusionary criteria. Mean average effect sizes were computed for seven primary learner characteristic cat- egories: (1) rapid naming, (2) alphabetic principle, (3) phonological awareness, (4) problem behavior, (5) memory, (6) IQ, and (7) demographic. The primary learner characteristics that influenced the treatment responsiveness of early literacy interventions were, in order of magni- tude, rapid naming, problem behavior, phonological awareness, alphabetic principle, memory, IQ, and demographics. With the exception of the demographic category, the obtained effect sizes for the primary learner characteristics were moderately large. The demographic primary learner characteristic (i.e., disability, ethnicity, grade-level status) of children was not statis- tically (p < 0.05) distinct from zero. The findings, limitations, and future research needs are discussed. Children who struggle learning to read represent one of the most significant challenges facing general and special ed- ucators today. Indeed, improving reading outcomes is one of the cornerstones of the reauthorization of the Elementary and Secondary Education Act—No Child Left Behind leg- islation (2001). No Child Left Behind represents a commit- ment by the federal government to ensure that every child can read by the end of third grade and to the use of sci- entifically based reading instruction programs in the early grades. It is expected that a major benefit of this approach will be to reduce the number of children identified as need- ing remedial or special education services due to a lack of appropriate reading instruction in their early years. In this context, it is of interest to review the program of research on early literacy interventions to determine the magnitude and relative contribution of learner characteristics on treatment effectiveness. A previous combined vote-counting and narrative review of the program of research on children who are nonrespon- ders (i.e., fail to benefit from generally effective early literacy interventions) illuminated much about the learner character- istics that appear to influence the treatment effectiveness of early literacy interventions (Al Otaiba & Fuchs, 2002). The review included a total of 23 studies in which researchers described the learner characteristics of children who were nonresponders. The overall findings reported by researchers from the 23 studies indicated that early literacy interventions clearly benefit most students. Reported estimates, however, of the percentage of children who were nonresponders var- ied widely (i.e., 8–80 percent) across the studies. This high Requests for reprints should be sent to J. Ron Nelson, Ph.D., Center for At-Risk Children’s Services, 202 Barkley Center, Lincoln, NE 68583-0732. Electronic inquiries may be sent to rnelson8@unl.edu. degree of variability may have been a function of several variables such as (1) the criteria used by researchers to oper- ationally define nonresponders (see Al Otaiba & Fuchs, 2002 for descriptions of the criteria used by researchers to opera- tionally define nonresponders), (2) characteristics of children in the samples, (3) effectiveness of the early literacy inter- vention, and/or (4) degree of treatment fidelity (Al Otaiba & Fuchs, 2002). Phonological awareness deficits were the most promi- nent learner characteristic of children who were nonrespon- ders. A majority of the researchers (n = 21) investigated the importance of phonological awareness to the acquisition of beginning reading skills. Of these 21 studies, a majority (n = 16) of the researchers reported that children who were nonresponders evinced phonological awareness deficits. The contribution, however, of phonological awareness deficits on children who were nonresponders appeared to be moder- ated if explicit instructional methods, rather than implicit ones, were used by the implementers (Al Otaiba & Fuchs, 2002). Al Otaiba and Fuchs (2002) also reported that a num- ber of other cognitive, behavioral, demographic, and ortho- graphic learner characteristics may influence the treatment effectiveness of early literacy interventions. Researchers re- ported that children who demonstrated slow letter-naming speed, difficulty encoding, storing, and organizing phonolog- ical information in memory, and had IQ deficits were found to be nonresponders. Attention or problem behaviors of chil- dren also influenced children’s responsiveness to early liter- acy interventions. Children who evinced problem behaviors appeared not to benefit from early literacy interventions even when they were delivered in a one-to-one instructional for- mat (e.g., Vadasy, Jenkins, Antil, Wayne, & O’Connor, 1997). Demographic characteristics found to influence children’s