Many students experience difficulties learning to program. They find learning to program in the object-oriented paradigm particularly challenging. As a result, computing educators have tried a variety of instructional methods to assist beginning programmers. These include developing approaches geared specifically toward novices and experimenting with different introductory programming languages. However, having tried these different methods, computing educators are faced with yet another dilemma: how to tell if any of these interventions actually "worked"? The research presented here was motivated by an interest in improving practices in computer science education in general and improving my own practices as a computer science educator in particular. Its purpose was to develop an instrument to assess student learning of fundamental and object-oriented programming concepts, and to use that instrument to investigate the impact of different teaching approaches and languages on students' ability to learn those concepts. Students enrolled in programming courses at two different universities in the Mid-Atlantic region during the 2009-2010 academic year participated in the study. Extensive data analysis showed that the assessment instrument performed well overall. Reliability estimates ranged from 0.65 to 0.79. The instrument is intrinsically valid since the questions are based on the core concepts of the "Programming Fundamentals" knowledge area defined by the 2008 ACM/IEEE curricular guidelines. Support for content validity includes: 71% of correct responses varied directly with the students' scores; all possible responses were selected at least once; and 21 out of 24 questions discriminated well between high and low scoring students. CS faculty reviewers indicated that 19 out of 24 questions reflected basic concepts and should be used again "as is" or with "minor changes." Factor analysis extracted three comprehensible components, "methods and functions," "mathematical and logical expressions," and "control structures," suggesting the instrument is on its way to effectively representing the construct "understanding of fundamental programming concepts." Statistical analysis revealed significant differences in student performance based on language of instruction. Analyses revealed differences with respect to overall score and questions involving assignment, mathematical and logical expressions, and code-completion. Language of instruction did not appear to affect student performance on questions addressing object-oriented concepts. [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.]