| Research Design: |
The experiment required a sample size of 162 centers (four-year-olds classrooms) to be randomly assigned -- 36 to each of the three curricula and 54 to the control group. Child care centers in Miami-Dade County were eligible to participate in the study if they served some children whose care was subsidized. They could also serve, if they chose to, other children from low-income families. The centers had to have at least one classroom with at least five four-year-olds enrolled at the time of recruitment. They could not be already testing or implementing a literacy curriculum. All children in the selected classrooms were eligible to participate.
The design called for a single classroom to be selected and centers to be grouped by agency affiliation and teacher's dominant language (i.e., the language she preferred to be trained in). For centers with more than one four-year-old classroom serving subsidized children, one classroom was chosen for the experiment. If one classroom had more subsidized children than the other(s), that classroom was selected. If two or more classrooms had the same number of subsidized children, then the one with the most children was chosen. If classrooms were equally large and had the same number of subsidized children, then one classroom was chosen randomly.
The recruitment and eligibility determination processes yielded a total of 300 eligible centers. Ultimately, 165 centers signed agreements to participate and received their assignments. There were no refusals after centers learned their assignments. Over the course of two years, eight centers left the study. Five left because the center was closed or sold to an owner who chose not to participate; only three left because the director decided not to continue with the curriculum to which they were assigned.
Two nationally-known curricula, Ready, Set, Leap! (RSL!) and Breakthrough to Literacy (BTL) and one locally developed curriculum, Building Early Language and Literacy (BELL), were chosen for testing. The three curricula selected differed in instructional approach, breadth of approach, materials provided, intensity and cost, but all three focused on the development of early literacy skills and knowledge. All three included take-home components (books and materials to be used by families with children at home) and tools that teachers could use to assess children?s progress in the curriculum. Each curricula provided some materials in Spanish for children with the aim of motivating reading, regardless of the language. All three meet the Florida Preschool Language and Literacy Learning Standards; two of the three, RSL! and BTL, also meet the state standards for a comprehensive curriculum, since they include math and science concepts.
For all three interventions, a single professional development model was agreed upon. The model had two important features: a staffing plan with several layers of supervision, and a training plan that featured three sequenced training sessions over an 18-month period, combined with ongoing mentoring and support over the entire period. |
