Tham khảo tài liệu 'human-robot interaction part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Development of a Virtual Group Walking Support System 105 In case of alone use first to familiarize the subjects with the use of the system the subjects were walking with the experimental system in 1 min. Secondly the subject urged to perform the exercise by himself under two conditions out of a-1 to a-3 and answer which condition he preferred. The experiments were performed with three combinations of three experimental conditions. After the experiment the subjects answered some questionnaire. In the case of partner s use the two subjects in different rooms performed the system with his partner and the subject urged to perform the exercise with his remote partner undo two conditions out of p-1 to p-3 and each subject answered which condition he preferred. The experiments were performed with three combinations of three experimental conditions. Experimental results Table 1 and 2 show the results of paired comparison. The number in the table shows that of subjects who preferred the line condition to the row condition. Most of subjects prefer the exercise with TV a-1 in the case of alone use. The Bradley-Terry model was assumed to evaluate the preference of the condition quantitatively defined as follows Okubo Watanabe 1999 p -n n n n const. 100 i 1 Where n intensity of i Pij probability of judgment that i is better than j Here n shows the intensity of preference of the experimental condition. The model enables to determine the preference based on the paired comparison see and 7 . The Bradley-Terry model assumed by using the result of paired comparison. And to approve the matching of the model the goodness-of-fit test and likelihood ratio test were applied to this Bradley-Terry model. As a result the matching of the model was consistent. a-1 a-2 a-3 Total a-1 14 15 29 a-2 6 5 11 a-3 5 15 20 Table 1. Result of paired comparison in case of alone use. Table 2. Result of paired comparison in case of paired use. 106 Human-Robot Interaction Fig. 6. Bradley-Teery .
