# Investigation of Interactive Strategies Used in Undertaking Collaborative Tasks
## 4 Experiments
### Experiment III: Tele-Assistance3 vs. Tele-Assistance7  
This experiment compared the effect of Tele-Assistance7 on performing the collaborative task with that of Tele-Assistance3. We used the same CVE and devices as those for Experiment I and Experiment II. Participants: There were a total of 18 participants (assuming the role of the novice), according to the sample size determined from a pilot study. All participants were in the same age group as those in Experiment I and were naive to the purpose of the experiment. They underwent the same vision and handedness tests as those in Experiment I. However, these 18 participants differed from their counterparts in Experiment I and Experiment II. Figure 6: Results of Experiment II: (**a**) Average completion time of the task; (**b**) Average error of performing the task; (**c**) Average number of operations executed by the participants; (**d**) Average workload perceived by the participants. (Error bars represent standard error). Procedure: The procedure of Experiment III was the same as that of Experiment I, with the exception that it followed the format of Tele-Assistance3 rather than Tele-Operation. We recorded and computed the same four performance parameters. Data analyses and results: The same data analyses were implemented as in Experiment I and Experiment II. UnderTele-Assistance3, the participants used a shorter length of time to complete the task than under Tele-Assistance7. As shown in Figure 7a, the participants took, on average, \(5.77\pm 0.21\) min to finish the task under Tele-Assistance3, compared to 6.70 \(\pm\) 0.25 min under Tele-Assistance7. These interactive strategies yielded a significant difference in the completion time (Z = \(-2.461\); \(p\) < 0.05). However, the errors of performing the task between the two interactive strategies were not significantly different (Z = \(-0.980\); \(p\) > 0.05). As illustrated in Figure 7b, Tele-Assistance3 yielded an error of 0.045 \(\pm\) 0.004 cm, whereas Tele-Assistance7 generated an error of 0.051 \(\pm\) 0.004 cm. Similarly, the interactive strategies produced no significant difference in the number of operations either (Z = \(-0.047\); \(p\) > 0.05). On average, the participants executed respectively 5.09 \(\pm\) 0.22 operations under Tele-Assistance3 and 5.14 \(\pm\) 0.24 operations under Tele-Assistance7, as shown in Figure 7c. Moreover, the participants perceived the overall workload to be less under Tele-Assistance3 (59.38 \(\pm\) 2.52) than under Tele-Assistance7 (64.56 \(\pm\) 2.57), as revealed in Figure 7d. This difference in the overall workload was statistically significant (Z = \(-2.580\); \(p\) < 0.05). Discussion: This experiment examined the task performance when the novice performed the collaborative task with the expert under different degrees of autonomy. In performing the task under Tele-Assistance3 and Tele-Assistance7, there were similarities, but a few distinct differences. The less time needed to complete the task under Tele-Assistance3 than Tele-Assistance7 might imply that the added overriding ability of the expert facilitated the novice in finishing the collaborative task faster. This addition between the expert and the novice had no significant impact on the number of operations used by the novice and the errors made while performing the task. This finding indicates that the high-level and symbolic communication used in the CVE aided in transmitting commands and maneuvering the manipulator object efficiently. The expert's overriding ability helped to reduce the overall workload perceived by the novice, because of his/her decreased autonomy (and responsibility). The novice might translate this decreased sense of responsibility in his/her ability to understand the expert's intention and perform the task with ease. Figure 7: Results of Experiment III: (**a**) Average completion time of the task; (**b**) Average error of performing the task; (**c**) Average number of operations executed by the participants; (**d**) Average workload perceived by the participants.