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The WWC review of interventions for Early Childhood Education addresses child outcomes in six domains: oral language, print knowledge, phonological processing, early reading and writing, cognition, and math. The studies included in this report cover four domains: oral language, print knowledge, phonological processing, and math. The findings below present the authors’ estimates and WWC-calculated estimates of the size and the statistical significance of the effects of Let’s Begin with the Letter People® on children.8
Oral language. The PCER Consortium (2008) analyzed the effectiveness of Let’s Begin with the Letter People® on oral language using the Peabody Picture Vocabulary Test–III (PPVT-III) and the Test of Language Development–Primary: III (TOLD-P:3). The authors report, and the WWC confirms, that differences between Let’s Begin with the Letter People® and the control group are not statistically significant or substantively important (that is, an effect size of at least 0.25) on any of these measures. Fischel et al. (2007) analyzed the effectiveness of Let’s Begin with the Letter People® on oral language using two measures: the PPVT-III and Comprehension. The authors report, and the WWC confirms, that differences between the Let’s Begin with the Letter People® and the control groups on these measures are not statistically significant or large enough to be substantively important. According to WWC criteria, these two studies show no discernible effects on oral language.
Print knowledge. The PCER Consortium (2008) analyzed the effectiveness of Let’s Begin with the Letter People® on the Test of Early Reading Ability (TERA-3), the Woodcock-Johnson–III (WJ-III) Letter-Word Identification subtest, and the WJ-III Spelling subtest. The authors report, and the WWC confirms, that differences between the Let’s Begin with the Letter People® and control groups are not statistically significant or large enough to be substantively important on any of these measures. Fischel et al. (2007) analyzed the effectiveness of Let’s Begin with the Letter People® on print knowledge using six measures: the Woodcock-Johnson–Revised (WJ-R) Letter-Word Identification subtest, the WJ-R Dictation subtest, the Get Ready to Read! screening test, Letters Known, Book Knowledge, and Print Conventions. The study reports significant differences favoring Let’s Begin with the Letter People® on two measures: the WJ-R Dictation subtest and the Get Ready to Read! screening test. The WWC was unable to 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. According to WWC criteria, these two studies show no discernible effects on print knowledge.
Phonological processing. The PCER Consortium (2008) analyzed the effectiveness of Let’s Begin with the Letter People® on phonological processing using the Preschool Comprehensive Test of Phonological and Print Processing (Pre-CTOPPP) Elision subtest. The authors report, and the WWC confirms, that differences between the Let’s Begin with the Letter People® and control groups are not statistically significant or substantively important on any of these measures. According to WWC criteria, this study shows no discernible effects on phonological processing.
Math. The PCER Consortium (2008) analyzed the effectiveness of Let’s Begin with the Letter People® on math using the WJ-III Applied Problems subtest, the Child Math Assessment–Abbreviated, and Shape Composition task. The authors report, and the WWC confirms, that differences between the Let’s Begin with the Letter People® and control groups are not statistically significant or large enough to be substantively important on any of these measures. According to WWC criteria, this study shows no discernible effects on math.
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 (as calculated by the WWC), the size of the difference between participants in the intervention and the comparison conditions, and the consistency in findings across studies (see the WWC Procedures and Standards Handbook, Appendix E).
8The level of statistical significance was reported by the study authors or, when 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. For the formulas the WWC used to calculate the statistical significance, see WWC Procedures and Standards Handbook, Appendix C for clustering and WWC Procedures and Standards Handbook, Appendix D for multiple comparisons. No correction for clustering was needed for the study by the PCER Consortium (2008) because its analysis corrected for clustering by using HLM, but a correction for multiple comparisons was needed, so the significance levels in this report may differ from those reported in the original study. In the case of Fischel et al. (2007), a correction for clustering was needed, so the significance levels may differ from those reported in the original study.
|Institute of Education Sciences
Early Childhood Education