There are relatively few empirical studies that examine whether using a competency-based education (CBE) approach results in increased student learning or achievement when compared to traditional education approaches. This study uses a quantitative research methodology, a nonexperimental comparative descriptive research design, and a two-group pretest-posttest comparison of archival data to investigate whether a statistically significant difference exists between the gains in student achievement of institutional competencies for students who attended a traditional version of the U.S. Air Force resident Noncommissioned Officer (NCO) Academy in 2011 and the gains in student achievement of institutional competencies for students who attended a redesigned CBE version of the resident NCO Academy in 2013. The population studied consisted of 18,002 students that attended the NCO Academy in 2011 and 2013. Using a power analysis on repeated measures analysis of variance (ANOVA) with two groups (2011 sample and 2013 sample), two measurements (pretest and posttest), power of 0.80 (80%), small effect size (f = 0.10), and alpha level of 0.01 (99% confidence level), the sample size was determined to be 62. A random sample of 62 students was selected from the 2011 and the 2013 NCO Academy populations and the archived data from their pretest-posttest scores were analyzed using a repeated-measures ANOVA test. The findings revealed that a statistically significant difference exists between the gain scores of students who attended the 2011 traditional (content-based) course and the gain scores of students who attended the 2013 redesigned CBE (outcomes-based) course, F(1, 120) = 5.73, p = 0.018. The 2013 CBE NCO Academy students had slightly higher gains in student achievement than the 2011 traditional NCO Academy students. [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.]