The SIOP Model is a research-based model for providing Sheltered Instruction to English Language Learners (ELLs) within the mainstream classroom. Developed by Center for Research on Education, Diversity & Excellence (CREDE) researchers, Jana Echevarria, MaryEllen Vogt and Deborah J. Short, the SIOP Model includes eight components for making content comprehensible: Preparation, Building Background, Comprehensible Input, Strategies, Interaction, Practice & Application, Lesson Delivery, and Review & Assessment. The following categories include features and tips for practice provided according to each of the eight components of the sheltered instruction observational protocol.