Tracking is the process of sorting students into different curriculum tracks, such as academic, general or vocational, based on student's abilities, interests, and needs. Ability grouping pertains to academic subjects and is the process of placing students with similar skills and abilities into levels, such as an honors level course or a regular level course. This study defines a track as the course level in which a student is enrolled within an academic subject, such as remedial, regular, or honors. The purpose of this research study is to further explore the relationship between academic tracks and student achievement and to expand on previous methods of analyses. The study analyzes student achievement in mathematics, reading, and science based on placement into mathematics, English, and science tracks. A multilevel growth model is applied to analyze students' growth rate between 9th and 11th grades and the impact that students' ascribed characteristics and track placement have on student achievement over time. Results from the study find that overall there is variation in student growth rates in mathematics, reading, and science achievement and students' ascribed characteristics of race, meal status, and gender, as well as the track in which they are enrolled, do have an impact on student achievement. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]