Because results from TIMSS 2007 showed a gap in mathematics and science achievement between students in the United States and those in the top-performing countries, TIMSS 2007 data were used to investigate how school effectiveness factors known to be strongly associated with higher STEM achievement operated in the United States compared to Chinese Taipei, the Czech Republic, Singapore, and Slovenia. In each of the five countries, multilevel modeling was used to examine STEM achievement in relation to 11 school effectiveness factors associated with school resources, fidelity of curriculum implementation, and school climate, controlling for student home resources. A secondary purpose of this dissertation research was to help the TIMSS & PIRLS International Study Center prepare for multilevel modeling planned for the TIMSS and PIRLS 2011 data. Findings from this research showed that across the five countries, there were differences in how important school effectiveness factors operated. Teacher preparation, teaching the curriculum, and using instructional strategies involving reasoning and inquiry all were important school characteristics related to STEM achievement in some countries. A school environment conducive to learning emerged as being strongly associated with high STEM achievement in three of the countries, including the United States. Both absence of discipline and attendance problems as well as a school climate supportive of academic success were important predictors of student STEM achievement. This dissertation research also showed the potential of using TIMSS data as a basis for conducting school effectiveness analyses across different country contexts. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]