The study was conducted in 18 schools (31 classrooms) in Florida, Kansas, and New Jersey.
In this study, 18 preschools were randomly assigned to intervention (10 schools) or comparison (8 schools) conditions. Prior to random assignment, schools were sorted
into blocks on a number of conditions, including teacher experience, school location, and state report card score. Random assignment occurred within each block. From
the schools, 31 preschool classrooms participated in the study (14 intervention classrooms and 17 control classrooms). Participants included 215 preschool-age children
whose parents consented to their participation in the study. At baseline, children were an average 4.7 years old, half were male, half were African-American, and 14% were
reported as having a disability. Although the intervention and comparison groups were similar in race and disability status, the treatment group had more boys (61%) than the
comparison group (38%), a difference that was statistically significant. Attrition from the analysis sample (children with parent consent) was low: 2% at baseline, 5% at endof-
preschool posttest, and 10% at end-of-kindergarten follow-up. Response rates varied by measure but were comparable across treatment and control groups.
Intervention group children participated in Curiosity Corner. A Success For All (SFA) implementation measure was used by SFA trainers, who visited each classroom at least
three times during the year and rated the implementation of each classroom. Fidelity of the classrooms was rated on a four point scale, ranging from “Not at all” (0) to “High”
(3). The average fidelity score of the intervention classrooms was 2.0.
The comparison condition varied across schools. Comparison schools in Florida primarily used the Creative Curriculum. The Kansas comparison schools participated in a
blend of the Preschool and Language Stimulation curriculum and the Animated Literacy curriculum. Comparison schools in New Jersey used a teacher-developed curriculum.
Comparison classrooms were visited twice a year by the trainers and rated using the same implementation measure as was used for the intervention classrooms. The average
fidelity score of the comparison classrooms was 1.9.
The primary outcome domains assessed were the children’s oral language, print knowledge, phonological processing, and math. Oral language was assessed with the Peabody
Picture Vocabulary Test-III (PPVT-III) and the Test of Language Development-Primary III (TOLD-P:3) Grammatic Understanding subtest. Print knowledge was assessed
with the Test of Early Reading Ability-III (TERA-3), Woodcock-Johnson III (WJ III) Letter-Word Identification subtest, and the WJ III Spelling subtest. Phonological processing
was assessed with the Preschool Comprehensive Test of Phonological and Print Processing (Pre-CTOPPP) Elision subtest. Math was assessed with the WJ III Applied
Problems subtest, the Child Math Assessment-Abbreviated (CMA-A), and the Building Blocks, Shape Composition task. For a more detailed description of these outcome measures, see Appendices A2.1–2.5.
Support for implementation
Success for All staff provided an initial training session for the intervention teachers and ongoing implementation support, including three visits a year to conduct observations and provide feedback.