Which science programs have been proven to help elementary students to succeed? To find out, this review summarizes evidence on three types of programs designed to improve the science achievement of students in grades K-6: (1) Inquiry-oriented programs without science kits, such as Increasing Conceptual Challenge, Science IDEAS, and Collaborative Concept Mapping; (2) Inquiry-oriented programs with science kits, such as Insights, FOSS, STC, SCALE, and Teaching SMART; and (3) Technology programs, such as BrainPOP, The Voyage of the Mimi, and web-based labs. A literature search of articles written between 1980 and 2011 was carried out to find studies that met the following criteria: (1) The studies compared children taught in classes using a given science program or practice with those in control classes using an alternative program or standard methods; (2) The program or practice had to be one that could, in principle, be used in ordinary science classes (i.e., it did not depend on conditions unique to the experiment); (3) Random assignment or matching with appropriate adjustments for any pretest differences (e.g., analyses of covariance) had to be used, and studies without control groups, such as pre-post comparisons and comparisons to "expected" scores, were excluded; (4) Pretest data had to be provided, unless studies used random assignment of at least 30 units (individuals, classes, or schools) and there were no indications of initial inequality; (5) The dependent measures included quantitative measures of science performance that were not excessively aligned with the experimental (but not control) treatment; (6) A minimum study duration of 4 weeks was required; and (7) Studies had to have at least two teachers and 15 students in each treatment group. A major finding of this review is the fact that there are very few rigorous experimental evaluations of elementary science programs. After an exhaustive search involving examination of 327 published and unpublished articles, only 17 studies met the inclusion criteria. The evidence from studies that met the inclusion criteria supports a view that improving outcomes in elementary science depends on improving teachers' skills in presenting lessons, engaging and motivating students, and integrating science and reading. Technology applications that help teachers teach more compelling lessons and that use video to reinforce lessons also have promise. [For the full report, "Effective Programs for Elementary Science: A Best-Evidence Synthesis," see ED539695.]