The "ex post facto" causal-comparative study examined the academic achievement of high school students who took their dual credit English or mathematics college credit-bearing course in two different environments, namely, the college setting and the high school setting. Due to non-experimental nature of the study, no causal inferences were drawn. The non-probability sample consisted of 428 students who had taken the English dual credit course of which 342 were off-campus and 86 had taken the course on campus. There were 82 students who had taken the mathematics dual credit course of which 25 were off-campus students and 57 had taken the course on campus. The English and mathematics achievement grades were treated as ordinal data and Mann-Whitney U test showed that group differences on the basis of outcome measures were not statistically significant. The results suggest that when each setting adheres to the rigor of dual credit program standards, academic quality is maintained, academic achievement is comparable between students in the two settings, and college level learning is achieved. [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.]