In the U.S., the EL student population in public schools continues to grow and it raises the question on how to effectively instruct and prepare these students to achieve academic proficiency. The purpose of this quantitative study is to determine if and to what extent there is a quantitative link between gains from 2nd to 3rd grade where the length of the program was 4-hours with both SIOP and target and explicit ELD methods, and gains from 3rd to 4th grade where 3rd grades length of program was 4-hours and 4th grades length of program was 2-hours with both SIOP and target and explicit ELD methods, culminating with the interaction between time (2nd-3rd grade and 3rd-4th grade) and program (SIOP and targeted and explicit ELD) in gains of English language proficiency. The study's theoretical foundation came from the theory of second language acquisition (SLA) and the theory of constructivism. The research participants totaled 325 elementary school ELs located in south-central and south-eastern Arizona. AZELLA data consisting of scale scores from the domains of reading, writing, listening, and speaking of English language proficiency were used for this study. Results of the mixed ANOVA showed that the main effect difference in gains between the lengths of 4-hr/4-hr and 4-hr/2-hr indicated a significant difference F(1,323) = 113.85, p < 0.001. The main effect for difference in gains between SIOP vs. targeted and explicit ELD also showed a significant difference F(1,323) = 133.92, p < 0.001. While the results of the interaction effect on English language proficiency indicated a significant difference between length of ELD and method of ELD F(1,323) = 136.62, p < 0.001. The results of this study could contribute to future legislative policy centered around length of instruction and instructional method for ELs. [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.]