The study was conducted in a county in central Florida during the 2007–08 and 2008–09
The study used a randomized cluster experimental design. Volunteer teachers were matched
on student demographics and grade level and then were randomly assigned to either the intervention group or the comparison group. Over a two-year period, 140 teachers were randomly
assigned—70 to the intervention group and 70 to the comparison group. The total analysis
sample across both years included 66 teachers in intervention classrooms and 59 teachers in
comparison classrooms. The overall and differential attrition rates of teachers (11% and 10%,
respectively) met WWC standards for low attrition.
The student analysis sample included 1,418 students who received the GEMS® Space Science
Sequence and 1,176 comparison group students who received the typical space science
instruction available in the district. Attrition rates of students were unknown. About 40% of
these students were in the fourth grade; the rest were fifth graders. The students were evenly
split between boys and girls (50% male, 50% female). Almost one-third (31%) were eligible
for free and reduced-price lunch. About 62% of the students were White. Three percent of the
sample were English language learners.
The study reported students’ outcomes immediately following completion of the space science
sequence. These findings can be found in Appendix C. Additional findings reflecting students’
follow-up outcomes five months after the completion of the space science sequence can be
found in Appendix D.
Students in the intervention group received GEMS® Space Science Sequence (Lawrence
Hall of Science, 2007) for grades 3–5, which was designed to address age-appropriate core
concepts in space science and common misconceptions that students might have about
them. Students investigated size and scale relative to distance, the Earth’s shape and gravity,
how the Earth moves, and moon phases and eclipses in four units, over 24 sixty-minute class
sessions. The curriculum had an explicit focus on the role of models and evidence in science.
Throughout the unit, students evaluated alternative explanations and used evidence to support
explanations and to critique the merits of an explanation.
Comparison teachers used the standard district text for grades 4 and 5 to address the same
space science content as the intervention group. The district curriculum was centered on a
more didactic presentation of space science concepts, including direct instruction, reading of
text, and students answering very focused questions.
Student outcomes were assessed with the Space Science Content test (Sadler, Coyle,
Cook-Smith, & Miller, 2007). The assessments were given to students prior to space science
instruction, two weeks following completion of teaching the space science unit, and at
the five-month follow-up. For a more detailed description of these outcome measures, see
Appendix B. The study also used assessments that did not meet inclusion criteria as outcome
measures for the Science topic area: the Homerton Science Attitudes survey, the Models and
Evidence Questionnaire, and Views of Scientific Inquiry.
Support for implementation
Teachers in the intervention condition were given four days of preservice professional development
to learn about the specific curriculum before the school year, a three-hour follow-up
training before the curriculum was implemented, and access to a “science coach” midway
through teaching the unit that was tested. In addition, all teachers were offered basic professional
development related to the new textbook being used by the district in all space science
classes. Teachers in both groups were instructed to refrain from adding any activities to those
present in their assigned curriculum. The study does not provide information on the education
or experience of teachers.