Differentiating instruction allows the teacher to build in different scaffolds for different groups of students, using what they know about their students and what the teacher wants the students to know. Here are some guiding questions for the teacher according to (Rutherford 2002). How abstract are the ideas? Does the teacher need to make the ideas more concrete for the students? Does the teacher need to use realia, pictures, and graphs to help make the content comprehensible? What are the connections to the students' background knowledge? What materials and resources can the teacher provide? Are there graphic organizers that help to build schema? Are there specific metacognitive learning strategies such as organizational planning or cognitive learning strategies such as summarizing chunks of text that will help the English language learners break the task into smaller parts? What is the level of independence? Does the teacher need to provide language structures to facilitate English language learners? What is the pacing? Do the students need more time to complete the assignment? According to Tomlinson and Strickland (2005), teachers usually differentiate instruction by adjusting one or more of the following; the content, what students learn; the process, how students learn; or the product, how students demonstrate their mastery of the knowledge or skills. However there is no one size fits all model for differentiated instruction. It looks different depending on the prior knowledge; interests and abilities students bring to the learning situation. Tomlinson describes teachers who differentiate as those who strive to do whatever it takes ensure that struggling and advanced learners, students with varied cultural heritages, language proficiencies, and children with different background experiences all grow as much as they possibly can each day, each week, and throughout the year.