Like no other text on the market, Making Content Comprehensible presents an empirically validated model of sheltered instruction. This text provides the Sheltered Instruction Observation Protocol (SIOP) model, which provides school administrators, staff developers, teachers, teacher candidates, university faculty, and field experience supervisors with a tool for observing and quantifying a teacher's implementation of quality sheltered instruction. Making Content Comprehensible presents a coherent, specific, field-tested model of sheltered instruction that specifies the features of a high-quality sheltered lesson that teaches content material to English learners. Each of the 30 items from the SIOP model are illustrated through vignettes. Three different lessons for each item are rated and discussed, allowing the book to be applied to a variety of content areas and grade levels.