In most elementary classrooms, some students struggle with learning, others perform well beyond grade-level expectations, and the rest fit somewhere in between. Within each of these categories of students, individuals also learn in a variety of ways and have different interests. To meet the needs of a diverse student population, many teachers differentiate instruction. This Digest describes differentiated instruction, discusses the reasons for differentiating instruction and what makes the approach successful, and suggests how teachers can start implementing this type of instruction. The Digest notes that teachers can differentiate at least four classroom elements based on student readiness, interest, or learning profile: (1) content--what the student needs to learn or how the student will get access to the information; (2) process--activities in which the student engages in order to make sense of or master the content; (3) products--culminating projects that ask the student to rehearse, apply, and extend what he or she has learned in a unit; and (4) learning environment--the way the classroom works and feels. The Digest also discusses reasons for differentiating instruction, including the ample evidence that students are more successful in school and find it more satisfying if they are taught in ways that are responsive to their readiness levels. Noting that there is no recipe for differentiation, the Digest suggests broad principles and characteristics that are useful in establishing a defensible differentiated classroom. The Digest concludes with suggestions for teachers as they begin to differentiate, begin to differentiate more proactively, or seek to refine a classroom that can already be called "differentiated." (LPP)