Classmate Intelligence as a Contextual Influence on Individual Reading Achievement

Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

William C. Goggin

Advisor Department



This study conceptualized average student intelligence as an important element of the classroom learning context and examined its influence as a source of variance in reading achievement at the level of the classroom, and the individual student. Participants included 1858 students from the second-. third- and fourth-grade classes of 17 inner-city schools that were participating, in an ongoing longitudinal study of the acquisition of reading skills. Eight schools were from the Houston Independent School District, and nine schools were from the District of Columbia Public Schools. The two-level analysis used hierarchical linear modeling to examine the relationship between classroom mean WISC and achievement, a measured by three subtests of the Woodcock Johnson-Revised Tests of Achievement. For all grade/district groups, the proportion of between-classroom variance explained by classroom mean WISC ranged from negligible (1%) to substantial (88%). Within a grade/district group, higher classroom mean WISC was associated with higher mean achievement for the classroom. In some grade/district groups, a higher classroom mean WISC was also associated with a stronger relationship between intelligence and achievement for students in that classroom. Classroom mean WISC explained 6-48% of the variance in individual outcome. In three of twenty-four instances, significant variance in individual achievement was also partially explained by the interaction of classroom mean WISC and individual WISC relative to achievement. The strength, significance, and direction of this moderating effect were unique to the affected grade/district groups, which suggested that the moderating effect was idiosyncratic to the particular students and classrooms that were sampled. As a general finding, classroom mean WISC explained more of the between-classroom variability in achievement, and less of the within-classroom variability in achievement, for the Houston Independent School District than for the District of Columbia Public Schools.