toy train. To get the toy, he must first communicate to his therapist that he wants it. His desire to play is strong enough to be considered intrinsic motivation because it is a natural feeling, and his desire to communicate with his therapist to get the train can be considered extrinsic motivation because the outside object is a reward (see incentive theory). Communicating with the therapist is the first, the slightly more challenging goal that stands in the way of achieving his larger goal of playing with the train. Achieving these goals in attainable pieces is also known as the goal-setting theory. The three elements of goal-setting (STD) are Specific, Time-bound, and Difficult. Specifically, goals should be set in the 90th percentile of difficulty. Intrinsic motivation comes from one's desire to achieve or attain a goal. Pursuing challenges and goals come easier and more enjoyable when one is intrinsically motivated to complete a certain objective because the individual is more interested in learning, rather than achieving the goal. Edward Deci and Richard Ryan's theory of intrinsic motivation is essentially examining the conditions that “elicit and sustain” this phenomenon. Deci and Ryan coined the term “cognitive evaluation theory" which concentrates on the needs of competence and autonomy. The CET essentially states that social-contextual events like feedback and reinforcement can cause feelings of competence and therefore increase intrinsic motivation. However, feelings of competence will not increase intrinsic motivation if there is no sense of autonomy. In situations where choices, feelings, and opportunities are present, intrinsic motivation is increased because people feel a greater sense of autonomy. Offering people choices, responding to their feelings, and opportunities for self-direction have been reported to enhance intrinsic motivation via increased autonomy. An advantage (relative to extrinsic motivation) is that intrinsic motivators can be long-lasting, self-sustaining, and satisfying. For this reason, efforts in education sometimes attempt to modify intrinsic motivation with the goal of promoting future student learning performance, creativity, and learning via long-term modifications in interests. Intrinsic motivators are suggested to involve increased feelings of reward and thus may support subjective well-being. By contrast, intrinsic motivation has been found to be hard to modify, and attempts to recruit existing intrinsic motivators require a non-trivially difficult individualized approach, identifying and making relevant the different motivators needed to motivate different students, possibly requiring additional skills and intrinsic motivation from the instructor. Extrinsic motivation Extrinsic motivation comes from influences