Carol Ann Tomlinson defines differentiated instruction as teaching with student variance in mind. It means starting where the kids are rather than adopting a standardized approach to teaching that seems to presume that all learners of a given age or grade are essentially alike. Thus differentiated instruction is “responsive” teaching rather than “one-size-fits-all” teaching.

A fuller definition of differentiated instruction is that a teacher proactively plans varied approaches to what students need to learn, how they will learn it, and/or how they can express what they have learned in order to increase the likelihood that each student will learn as much as he or she can as efficiently as possible.