The distinction between intrinsic and extrinsic motivation is difficult to make in some instances. when studying motivational patterns in sixth-grade science classrooms, Lee and Brophy (1996) found it useful to distinguish among students motives in multiple ways. The students who constructs the science fair project may enjoy the process, particularly because the student selected the topic , but may also be motivated by the prospect of receiving a prize , an award ribbon, or entry into a higher-level science fair.