## 4 Discussion  
In the present study, we demonstrated an effective learning method (practice using a simulation robot vs. practice among students) for teaching therapeutic motion techniques to university students. The results revealed no significant change in the kinematics data after practice in the Robo and Human groups; in addition, the results showed no significant differences between the two groups across any domains. These results suggest that there was no change in the upper limb therapeutic motion techniques in both practice methods. However, the machine learning data of students and therapists showed that there were significantly more students in the Robo group than in the Human group who, after practice, were judged to have the same therapeutic motion techniques as the therapists. Although there was no difference in the kinematics data between the two groups, it was suggested that the number of students who practiced using a robot showed greater improvement in their therapeutic motion techniques than did those who practiced among students. Muscle tone in hemiplegic stroke patients tends to be speed-dependent, which means that muscle tone tends to increase when the participant moves rapidly [16]. The SAMO used in this study incorporates a speed-dependent mechanism; when the elbow joint is moved rapidly, the resistance received by the operator increases. As the resistance experienced by the operator increases, they would need to apply a greater force to move the elbow joint. Meanwhile, when the operator moves the elbow joint slowly, the corresponding resistance decreases, resulting in a decrease in the force exerted on the operator to move the elbow joint. Therefore, we speculated that the students felt a sense of resistance from the robot during the practice and performed exercise therapy while determining the speed that allowed easy movement. However, in practice between students, the student playing the role of the patient was not sick; therefore, the student playing the role of the therapist did not feel any resistance when moving the elbow joint. Thus, we deduced that the student had difficulty understanding the appropriate movement speed for the patient and that the treatment objective was unclear. Students are educated via various methods. Among these methods, it is effective to provide education that meets the differences and needs of each learner, such as learning style, culture, language, gender, personality, preferences, and living environment, as well as learning ability. This educational method is called differentiated instruction [17; 18]. The results of this study revealed that some students improved their therapeutic motion techniques by practicing with a robot alone. However, other students could not improve their therapeutic motion techniques even after practicing with the same robot. While moving the elbow joint of the robot, students were divided into those who read various information and applied it to their techniques and those who had difficulty applying this information to their techniques. This difference seems to be associated with the ability of individual students. Therefore, it is important to provide education according to the degree of acquisition of therapeutic motion techniques by students, based on the differentiated instruction method. This study had three main limitations. The first was regarding the relatively small number of practice sets. The number of practice sets in the present study was set to determine the effectiveness of the number of practice sets that could be performed during one class period, and a total of 30 sets were established for both groups. Studies on the effect of practice aimed at skill improvement reported that a practice effect was noted after 20 sets of a free-throw task in basketball [19] and after 40 practice sets of throwing darts