English learners (ELs) are becoming an increasing part of today's classrooms. This thesis takes a look at one method being used in schools today called Sheltered Instruction Observation Protocol (SIOP). This paper reviews current methods and programs being used to educate ELs and then describes the SIOP in detail. The study done for this thesis compared the reading comprehension of two first grade classrooms, one classroom which received reading instruction with SIOP and one which received reading instruction without. The results from this study showed that the classroom that received the reading instruction with SIOP had more growth in reading comprehension than the classroom without SIOP.