The purpose of this study was to analyze the effectiveness and the fidelity of fraction
problem-solving intervention programs. To meet the research purpose, the research questions
were established as follows: First, how did the selected studies consist their content elements
of the program and how was each study’s fidelity turned out? Second, how were the selected
studies’ effect sizes turned out? Third, is there any correlation between the program fidelities
and effect sizes of the selected studies in relation to research design? The researcher selected 10
studies on fraction problem-solving intervention from 2004 to 2014. Seven studies employed AB
design and the other three did experiment/control design. The results were as follows. First, the
selected studies’ contents fidelities appeared from 36.1 to 83.3 percent point. Second, the effect
sizes were turned out from 1.22 to 16.2. Third, the study employing multiple baseline design
that was scored highly on the fidelity rubric only showed higher effect size. Regrading these
findings, there was discussed some aspects and each study’s result in terms of their fidelity and
effect size in the discussion.