The study took place in 40 Head Start and state-funded preschool classrooms in California and
New York. The classrooms were from four programs in California and two programs in New York.
The study, conducted during the 2003–04 and 2004–05 school years, included an intervention
group implementing Pre-K Mathematics with DLM Early Childhood Express Math software and
a comparison group. In the 2002–03 school year (the study’s pilot year), teachers who volunteered
to participate in the study were blocked by program type and randomly assigned to
either an intervention group or a comparison group except for two pairs of classrooms, where
randomization was conducted within the pair. In the study’s evaluation year (2003–04), 33 of the
40 teachers were retained, and seven teachers were added using processes that were not consistent
with the original random assignment design. In one site, three replacement classrooms
were randomly selected, but the probability of selection to the intervention group was 66%,
higher than the original 50% probability at the start of the study. In the other site, three teachers
were nonrandomly placed into classrooms that were originally randomly assigned to intervention
or comparison groups, and another teacher was randomly selected from among volunteers
to fill an open teaching position in a study classroom. This resulted in a sample of 40 teachers (20 intervention, 20 comparison) in the 2003–04 school year. Thus, for most of the classrooms,
the intervention condition had been in place for a full year when the evaluation year
started. After parental consent was obtained, the sample included 316 children at baseline;
297 children were included in the analytic sample (148 intervention, 149 comparison). Baseline
equivalence between the analytic sample of intervention and comparison children was established
based on baseline outcome measures data provided by the study authors. At baseline,
children in the study classrooms averaged 4.3 years of age; 48% were male; 45% were
African American, 23% were Hispanic, and 18% were Caucasian. Ten percent of the children
were identified as having a disability.
Teachers conducted mathematics activities from Pre-K Mathematics twice a week with groups
of four to six children for approximately 20 minutes per group. During each classroom session,
teachers completed Assessment Record Sheets that were tied to the mathematics activity in
that session. Twenty-nine classroom activities were completed, and teachers sent 19 home
activities and materials for children to complete at home. Materials for home mathematics
activities were sent home every 1 to 2 weeks. Pre-K Mathematics was supplemented with
the DLM Early Childhood Express Math software, which included 26 numerical, quantitative,
geometric, and spatial activities. The software program provided individualized mathematics
instructional activities approximately twice a week. The intervention took place over 36 weeks.
In addition, teachers used a pre-existing general curriculum in their classrooms (curricula
included The Creative Curriculum®, High/Scope, Montessori, or specialized literacy curricula
and curricula developed by local teachers and school districts).
The business-as-usual comparison group participated in the curriculum used in their programs,
such as The Creative Curriculum®, High/Scope, Montessori, or specialized literacy
curricula and curricula developed by local teachers and school districts.
The outcome domains of oral language, print knowledge, phonological processing, and math
were assessed with standardized measures. Oral language was assessed with the Peabody
Picture Vocabulary Test, Third Edition (PPVT-III) and the Grammatic Understanding subtest
of the TOLD-P:3. Print knowledge was assessed with the TERA-III and the WJ-III Letter-Word
Identification and Spelling subtests. Phonological processing was assessed with the Pre-
CTOPPP Elision subtest. Math was assessed with the WJ-III Applied Problems subtest, the
CMA-A, and the Building Blocks Shape Composition test. The pretest assessment was conducted
in the fall of the 2003–04 school year, and the posttest assessment in the spring of the
same school year, when the children in the sample attended preschool. Trained research staff
administered all assessments. For a more detailed description of these outcome measures,
see Appendix B.
Support for implementation
During the 2002–03 school year (the evaluation year), intervention teachers participated in
a 4-day training workshop. Ongoing on-site training was provided approximately twice per
month. Prior to the 2003–04 school year, teachers in the intervention group received a 2-day
refresher workshop. Project staff observed and rated implementation fidelity of the small
group sessions once or twice a month and provided feedback to teachers.