Differentiating student affect means modifying the learning environment to meet student emotional needs. Our emotions and feelings, which are created by our past experiences and our reactions to current experiences, influence our self-concept, as well as motivation to learn and ability to collaborate. All these factors play a key role in the learning process. For example, “we differentiate by student affect when we have kids who need a little bit more attention to be able to stick with the task, or when we understand that this kid really, really likes to have someone acknowledge that he's made a great step forward,” says Tomlinson, “whereas this kid is kind of modest and would prefer really that attention not be called to him or her, but rather to the group because it's a cultural thing that the group needs to be acknowledged.” Addressing students‟ affective needs should be taken into consideration when planning such aspects of instruction as respectful tasks and flexible grouping, explains Tomlinson. “We [may] have some kids who don't work especially well in groups because they have emotional challenges, and we try to help develop groups and help them develop mechanisms for working in those groups to be successful.” Reference