This study reviews research and data to determine whether student achievement is affected by the high school scheduling model, and whether changes in scheduling models result in statistically significant changes in student achievement, as measured by the ACT Composite, ACT English Language Arts, and ACT Math scores. The high school scheduling models included in this study are: six period semester (SPS), five period trimester (FPT), seven period semester (VPS), standard 4x4 block (SB), and alternate day block (ADB). Supportive and non-supportive research are discussed in regard to the impact of the student scheduling model 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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]