Research

Five studies reviewed by the WWC investigated the effects of Let’s Begin with the Letter People^®. Two studies (Fischel, Bracken, Fuchs-Eisenberg, Spira, Katz, & Shaller, 2007; PCER Consortium, 2008) are randomized controlled trials that meet WWC evidence standards. The remaining three studies do not meet WWC evidence standards.

Meets evidence standards

One study reviewed by the WWC (PCER Consortium, 2008) assessed the effectiveness of Let’s Begin with the Letter People^® as part of the Preschool Curriculum Evaluation Research (PCER) effort.⁶ The PCER Consortium (2008) used a randomized controlled trial design in which 19 preschool programs in Houston, Texas, were randomly assigned to implement Let’s Begin with the Letter People^®, to implement Doors to Discovery™, or to a control group. For the Let’s Begin with the Letter People^® versus control study, data were collected on 184 children (95 Let’s Begin with the Letter People^® and 89 control). Fifty-five percent of the children were male; 43% were Hispanic, 30% were Caucasian, and 13% were African-American; and 12% were reported to have a disability. Pretest data were collected in the fall and posttest data were collected in the spring of the preschool year. Follow-up kindergarten data were collected in the spring of the following year. The study investigated effects on oral language, print knowledge, phonological processing, and math. The control condition consisted of teacher-developed, nonspecific curricula with a focus on basic school readiness.

A second study (Fischel et al., 2007) examined the effectiveness of Let’s Begin with the Letter People^® and the Waterford Early Reading™ Level One curricula using a randomized controlled trial design in 27 full-day Head Start classrooms in six Head Start centers in southeastern New York State. In each of the two intervention conditions, one of the experimental curricula was used in conjunction with the High/Scope^® program that had been used by the Head Start programs for more than 10 years. Control classrooms used only the High/Scope^® program. Classrooms were randomly assigned in each of three years, and data were collected in each year. In the first year, three classrooms were assigned to each group. In the second year, intervention group classrooms continued in the same group, the control group classrooms were randomly assigned to an intervention group, and eight new classrooms were randomly assigned to the three groups. In the third year, intervention group classrooms again continued in the same group, control group classrooms were randomly assigned to an intervention group, and three new classrooms formed the control group. The original number of children in these classrooms over the three years was 507. The mean age was 4.3 years at pretest. Participating children were 42% African-American, 41% Hispanic, 8% multiracial, 7% Caucasian, and 2% other race/ethnicity. Approximately 14% of the children were identified as Spanish-language dominant at the outset of the study. Pretest data were collected in the fall and posttest data were collected in the spring of the preschool year. The study investigated effects on oral language and print knowledge. The WWC includes the data from children participating in classrooms that were newly-randomized to study groups in each year, because the classrooms that continued in the same study group in later years might have been chosen by some parents because of their curriculum. The WWC thus includes data for 132 children in eight Let’s Begin with the Letter People^® classrooms and 149 children in 11 control classrooms over the three-year period.

Extent of evidence

The WWC categorizes the extent of evidence in each domain as small or medium to large (see the WWC Procedures and Standards Handbook, Appendix G). The extent of evidence takes into account the number of studies and the total sample size across the studies that meet WWC evidence standards with or without reservations.⁷

The WWC considers the extent of evidence for Let’s Begin with the Letter People^® to be medium to large for oral language and print knowledge, and small for phonological processing and math. No studies that meet WWC evidence standards with or without reservations examined the effectiveness of Let’s Begin with the Letter People^® in the early reading and writing or cognition domains.