Effectiveness

Findings

The WWC review of interventions for beginning reading addresses student outcomes in four domains: alphabetics, fluency, comprehension, and general reading achievement. The studies included in this report cover two domains: fluency and comprehension. The findings below present the authors’ estimates and WWC-calculated estimates of the size and the statistical significance of the effects of Read Naturally on students.

Fluency. Two studies reported findings in the fluency domain. The Hancock (2002) study findings for this domain are based on students’ performance on the Curriculum Based Measure: Test of Reading Fluency. The study author did not find a statistically significant effect of Read Naturally on the fluency measure, and the effect was not large enough to be considered substantively important according to WWC criteria (that is, an effect size of at least 0.25).

The Mesa (2004) study findings for this domain are based on students’ performance on the test of Oral Reading Fluency. The study author presented the group mean difference between the Read Naturally group and the comparison group on the fluency measure, but did not evaluate its statistical significance. The WWC found that the effect was neither statistically significant nor large enough to be considered substantively important.

Comprehension. The Hancock (2002) study findings for the comprehension domain are based on the performance of Read Naturally students and comparison students on the Peabody Picture Vocabulary Test: Third Edition (PPVT-III), the Word Use Fluency test, and the Curriculum Based Measure: Cloze Probe. The study author did not find statistically significant effects of Read Naturally on any of these three measures. The average effect size was not large enough to be considered substantively important according to the WWC criteria.

Rating of effectiveness

The WWC rates the effects of an intervention in a given outcome domain as positive, potentially positive, mixed, no discernible effects, potentially negative, or negative. The rating of effectiveness takes into account four factors: the quality of the research design, the statistical significance of the findings, the size of the difference between participants in the intervention and the comparison conditions, and the consistency in findings across studies (see the WWC Intervention Rating Scheme).