Treatment Effects for Older Struggling Readers: An Application of Moderated Mediation.

This study used multigroup structural equations to evaluate the possibility that a theory-driven, evidence-based, yearlong reading program for sixth-grade struggling readers moderates the interrelationships among elements of the simple model of reading (i.e., listening comprehension, word reading, and reading comprehension; Hoover & Gough, 1990). Our specific interest was in the relation of theory, program, and evaluation. Our motivating assumptions were that 1) a well-designed, theory-based program affects performance in predictable ways and that 2) treatment effects may be present even when group differences in posttest means are not robust. The analysis sample comprised 327 students, 113 in the business-as-usual condition and 214 in treatment. We pretested students in the fall of sixth grade and collected posttest data in the fall of seventh grade. There were 217 cases in the posttest sample, 47 comparison students and 170 treatment students at posttest. The findings support the possibility that treated sixth-grade students improved in response to an intensive, yearlong intervention, when conceptualizing change in terms of predictable interrelationships of important underlying skills, rather than in terms of group mean differences at posttest. Specifically, the results suggest that verbal knowledge is less proximal to the reading comprehension of students who have become proficient in the use of text processing and reading comprehension strategies.