On a Friday afternoon math class, Chen Xiao (all names in this document are pseudonyms) appeared particularly serious and attentive. Holding a feedback device, he listened carefully to Li Lei, who was standing in front of the class and making a learning report. After that, Chen Xiao and the other children in the class would use their feedback devices to evaluate Li Lei’s presentation. Li Lei was randomly selected by the system to represent her group after group discussions. The feedback device had buttons from 1 to 9, and when the students pressed them, the system would automatically calculate the average score of the whole class, which would be Li Lei’s final score. The evaluation results of each judge like Chen Xiao were recorded by the system, and after the scoring was over, a classmate would be randomly selected to explain the evaluation reasons. Chen Xiao was worried that he might be selected and unable to provide a reason, so he did not dare to be even slightly distracted during Li Lei’s presentation. Through the use of feedback devices, every student in the class became an evaluator of the student on the stage. They felt a sense of responsibility and power, experiencing the feeling of being the master of the classroom, which prompted them to consciously listen carefully and actively participate in the evaluation.