Effects of instructional ratios on students' reading performance in a regular education program

The purpose of the present study was to extend the work of Roberts, Turco, and Shapiro, Journal of Psychoeducational Assessment, 9, 308-318 (1991) by examining the effectiveness of different instructional ratios of known (K) to unknown (UK) vocabulary words on the reading progress of 46 students. The four experimental conditions were as follows: (a) 80% K : 20% UK, (b) 50% K : 50% UK, (c) 20% K : 80% UK, and (d) an assessment-only group. Differences on dependent measures across the four experimental conditions were evaluated at the end of a 7-week drill intervention (28 sessions). The results suggest that the students acquired new information when instructional ratios were expanded beyond the 80%K:20% UK ratio (suggested by Gickling) and even the 50%K:50% UK ratio (suggested by Roberts et al., 1991). An inverse relationship was also established between the amount of instructional material presented and the percentage of material acquired during drill sessions. Overall findings are discussed that provide partial support for Gickling's suggested instructional ratios.