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Intervention: Waterford Early Reading Level One™

Effectiveness


Findings

The WWC review of interventions for early childhood education addresses children’s outcomes in six domains: oral language, print knowledge, phonological processing, early reading/writing, cognition, and math. Fischel et al. (in press) addressed outcomes in the oral language and print knowledge domains. The findings below present the authors’ and the WWC-calculated estimates of the size and statistical significance of the effects of Waterford Early Reading Level One™ on children’s performance. 7

Oral language. Fischel et al. (in press) analyzed the differences between the Waterford Early Reading Level One™ and business-as-usual comparison groups for two measures in this outcome domain [the Peabody Picture Vocabulary Test-III (PPVT-III) and Comprehension] and found no significant effects; the WWC confirmed this. Furthermore, the average effect size was neither statistically significant nor large enough to be considered substantively important according to the WWC criteria (that is, at least 0.25).

Print knowledge. Fischel et al. (in press) analyzed the differences between the Waterford Early Reading Level One™ and business-as-usual comparison groups for six measures in this outcome domain [Get Ready to Read! Screen,8 Letters Known, Woodcock Johnson-Revised (WJ-R) Letter Word Identification subtest, the WJ-R Dictation subtest, Book Knowledge, and Print Conventions] and found significant differences favoring Waterford Early Reading Level One™ on one measure, Get Ready to Read! Screen. The WWC could not confirm statistically significant findings for any outcomes in this domain. Furthermore, the average effect size was neither statistically significant nor large enough to be considered substantively important according to the WWC criteria (that is, at least 0.25).

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,7 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).

7 The level of statistical significance was reported by the study authors or, where necessary, calculated by the WWC to correct for clustering within classrooms or schools and for multiple comparisons. For an explanation, see the WWC Tutorial on Mismatch. See the Technical Details of WWC-Conducted Computations for the formulas the WWC used to calculate the statistical significance. In the case of Waterford Early Reading Level One™, a correction for clustering was needed. Fischel et al. (in press) included children from all classes in the analyses. The WWC focused on intervention effects for children in the unique classes only (i.e., those classes that had not previously participated in the study).
8 The WWC placed this measure in the print knowledge domain because the majority of the items are about print knowledge and the measure correlates most highly with other measures of alphabet knowledge.