Differentiated teaching, in which students are taught according to their actual levels of understanding and provided with tailored learning paths, is key to ensuring learning. However, the initial distribution of students’ foundational skills in a classroom is often very high. Even highly experienced, skilled, and motivated teachers will find applying differential teaching to the whole distribution of abilities challenging. For the average teachers, attempting to do so would cause them to spend virtually all their time teaching only foundational skills. They would have no time to teach higher-order thinking skills.

Technology can help address this constraint. Recent evidence shows that personalized technology-aided instruction yields absolutely large learning gains for all students, with relatively greater gains for academically weaker students. More importantly, such instruction can cover the whole distribution of students’ initial skills. With technology’s help to develop their students’ foundational skills, teachers can have time to help students develop their higher-order thinking skills.