States and school districts are searching for strategies to raise the college and career readiness of high school graduates--imperative in an era when postsecondary credentials are the key to good jobs, better pay, and stronger economies. The creation and implementation of higher graduation standards aligned to college and career expectations is the most visible and emblematic effort by states to ensure students are prepared to succeed after high school, but it is far from the only one. A policy strategy of increasing interest is the practice of providing students with the opportunity to take college courses while in high school, known as dual enrollment. The premise of dual enrollment is that high school students can enhance their chances for college success if they better understand what it takes to succeed in college: they do this by actually experiencing real college coursework, often earning "dual credit" for both high school and college. New research, conducted in Texas by Jobs for the Future (JFF), points to the effectiveness of dual enrollment as a strategy for improving postsecondary success. This study focused on the academic outcomes of 32,908 Texas students from the high school graduating class of 2004. Like some of these studies, the authors' research used rigorous quasi-experimental methods to control for factors other than dual enrollment that could explain student success by comparing dual enrollees to non-dual enrollees who are otherwise closely matched academically and socially. JFF's methodological approach, known as a propensity score matching model, enabled the authors to account for student background characteristics to the highest degree possible short of a randomized study. This greatly increases the certainty that the better college outcomes found for dual enrollment participants are due t o the effects of the dual enrollment courses they completed. Appended are: (1) Propensity Score Model; (2) Cohort, Treatment, and Control Group, by Region; (3) Educational Attainment of Treatment and Control Groups; (4) Test Scores by Treatment and Control Groups; (5) Odds Ratios for College Access Model; (6) Odds Ratios for College Completion Model; and (7) Dual-credit Study Methodology. (Contains 2 figures, 7 tables, and 15 endnotes.)