The Sheltered Instruction Observation Protocol (SIOP) aims to make course content comprehensible to ESL learners and is applicable at all levels of instruction. Since ESL learners may not share the cultural context and background needed for comprehension of the course content, additional planning steps in the SIOP model allow teachers to pace the class in ways that accommodate these differences. In addition to the usual components of lesson planning, such as preparation, lesson delivery and assessment, key elements of the the SIOP can help to boost comprehension and functionality in English, leading to greater parity with native speakers of the language.
According to SIOP, good lesson delivery begins with preparation, as the teacher organizes and collects needed materials. At this stage, the teacher anticipates needed steps on the way to mastery of the material and plans strategies to ensure student participation and success. The teacher also begins to build background knowledge about the topic by linking students' personal experiences to the course material and pointing out connections between other areas of past knowledge and the course content.
To help students understand the class content, the SIOP model includes comprehensible input. The teacher needs to ensure that tasks are thoroughly explained and all course materials and class procedures are clearly understood. This includes the use of additional classroom tools, such as visual aids. The teacher needs to modify speech and vocabulary as required for the students' level of language skills.
To improve language skills, as well as mastery of the course content, the SIOP recommends high levels of classroom interactivity, with frequent use of small groups, discussion topics and learning tasks. Interactivity also helps to build background and supports the creation of comprehensible input.
A key component of the SIOP is offering students the opportunity for hands-on practice and application of concepts and skills. Practicing skills with other students also supports other principles of the SIOP, especially interactivity and creating comprehensible input, since students can work on mastering course content and build language skills at the same time.