This dissertation addresses the research question: To what extent do secondary school science students attending the U.S. Particle Physics Masterclass change their view of the nature of science (NOS)? The U.S. Particle Physics Masterclass is a physics outreach program run by QuarkNet, a national organization of secondary school physics teachers and particle physicists partially funded by the National Science Foundation and the Department of Energy. The Masterclass is a one-day event in which high school physics students gather at a local research institution to learn about particle physics and the scientific enterprise. Student activities include introductory lectures in particle physics, laboratory tours, data analysis, and the discussion of their findings in a conference-like atmosphere. Although the Masterclass has been previously evaluated for students' learning of particle physics content, it was unknown if students' understanding of NOS changed after attending the Masterclass. This research concerns the problem of science literacy, specifically students' understanding of the nature of science (NOS). Previous research suggests that students do not implicitly acquire a sufficient understanding of NOS through the instruction of science content or through inquiry investigations. The literature suggests that sufficient understanding of NOS will only be successful if it is explicitly taught within a context. Unfortunately, research also suggests that many teachers do not include explicit instruction of NOS due various reasons that include a lack of time, understanding, and resources. Therefore, a need presents itself for curriculum extension programs in which explicit learning of NOS may occur. Due to the Masterclass explicitly including NOS within its introductory presentations, it was hypothesized that the remaining Masterclass activities may provide a context for student learning of NOS. The design of this study was a mixed methodology utilizing repeated quantitative and qualitative measures. Data collection consisted of a survey instrument consisting of Likert-type and open-response items administered as a pretest prior to the Masterclass, a posttest immediately following the Masterclass, and a second posttest administered two to three weeks after the Masterclass. Additional data were also collected through the use of phone interviews. Three different Masterclasses were evaluated over a two-year period at Fermilab (outside of Chicago) in February 2009 and February 2010 and at U.C. Irvine (outside of Los Angeles) in March 2010. The results of the combined analyses suggested students' understanding of NOS may have changed after attending the Masterclass, specifically in the NOS tenets regarding: indirect, subjective observations; use of imagination and creativity; collaboration; and the image of a scientist. Students' understanding of NOS did not appear to change in the NOS tenets regarding: tentative yet stable; social and cultural influences; no universal scientific method; and a comprehensive understanding of theory versus law. Although there are a number of outreach programs involving scientists in K-12 education, very few of them have been formally evaluated to determine if they provide adequate learning of NOS. Therefore, the significance of this study is that it provides data to support the claim that science outreach programs may be designed to address science literacy, specifically as a context for explicit NOS instruction. [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.]