Abstract
School districts in the U.S. have dedicated resources to increase the achievement of English language learners (ELLs), but despite their efforts, these students continue to lag behind their non-ELL peers (Farbman, 2015). In addition, content area teachers feel underprepared to meet the academic and linguistics needs of these students, because they have not received professional development training on a model that could improve their teaching practices and promote optimal learning outcomes (Gonzalez, 2016). The purpose of this quasi experimental, posttest-only design study was to examine the impact of the Sheltered Instruction Observation Protocol (SIOP) model on the achievement of ELLs in the content areas of reading, mathematics, and science as compared to ELLs who did not receive instruction with the model. Archival data on ELLs in grades 1-5 were obtained from a school district located in Southwest Florida. The sample consisted of 481 ELLs who received instruction with SIOP and 321 ELLs who received instruction with traditional methods. The data analysis revealed statistically significant differences in achievement levels in reading, mathematics, and science for students who received instruction with SIOP as measured by ACCESS for ELLs 2.0, FSA Reading, STAR Reading, FSA Mathematics, and Science Statewide Assessment. Results from this study suggested that using the SIOP model can have a positive impact on closing the achievement gap between ELLs and non-ELLs. The results also showed that even though the students’ performance in the SIOP group outperformed the students in the non-SIOP group, their scores fell within the lower range of achievement levels. Teachers, school administrators, district administrators, policy makers, and teacher educators are vested in the achievement of ELLs; therefore, the findings of this study can provide valuable implications to improve ELL academic performance.