In recent years, there has been a demand to teach engineering in high schools, particularly using a challenge-based curriculum. Many of these programs have the dual goals of teaching students the engineering design process (EDP), and teaching to deepen their understanding and ability to apply science and math concepts. Using both quantitative and qualitative methods, this study examines whether a high school design engineering program accomplishes each of the two goals. During the 2010-2011 school year, over 100 students enrolled in the same design engineering course in seven high schools. Evidence of learning and application of the EDP is accomplished by triangulating student interviews with pre-/post-tests of EDP-related questions and a survey of design engineering beliefs. To determine whether students could apply science and math concepts, we examined content test questions to see if students used science and math ideas to justify their engineering work, and triangulated these results with student interviews. The results are mixed, implying that although there is some learning, application is inconsistent.