# Investigation of Interactive Strategies Used in Undertaking Collaborative Tasks
## 4 Experiments
### Experiment II: Tele-Operation vs. Tele-Assistance3  
This experiment compared the effect of Tele-Operation on performing the collaborative task to that of Tele-Assistance3. In Experiment II, we utilized the same CVE and devices as those in Experiment I.  
Participants: There were a total of 16 participants (assuming the role of the novice, although one of them experienced a behavior disorder during the experiment and the data collected could not be used), according to the sample size determined from a pilot study. Although within the same age group as the participants in Experiment I, all of these participants differed from those in Experiment I. Similarly, all of these participants were naive to the purpose of Experiment II. They underwent the same vision and handedness tests as those in Experiment I.  
Procedure: The procedure of Experiment II was the same as that of Experiment I, except under Tele-Assistance3 rather than Tele-Assistance7. We recorded and computed the same four performance parameters.  
Data analyses and results: As in Experiment I, we employed the same data analyses. We found that the average completion time under Tele-Operation (4.40 \(\pm\) 0.22 min) was shorter than under Tele-Assistance3 (6.11 \(\pm\) 0.21 min), as shown in Figure 6a. The difference of the completion time between Tele-Operation and Tele-Assistance3 was statistically significant (\(Z=-3.351\); \(p<\) 0.05). As illustrated in Figure 6b, Tele-Operation yielded an average error of 0.03 \(\pm\) 0.01 cm, whereas Tele-Assistance3 resulted in an average error of 0.05 \(\pm\) 0.01 cm. The difference between these errors was statically significant (\(Z=-3.237\); \(p<\) 0.05). For the number of operations, the participants took, on average, 12.01 \(\pm\) 0.42 steps and 5.11 \(\pm\) 0.25 steps under Tele-Operation and Tele-Assistance3, respectively, revealing a significant difference of these steps (\(Z=-3.412\); \(p<\) 0.05) as seen in Figure 6c. However, the participants perceived the overall workload to be at the similar level for both Tele-Operation (57.09 \(\pm\) 3.73) and Tele-Assistance3 (58.47 \(\pm\) 3.00). There was no statistically significant difference observed between the perceived workload for either format (\(Z=-0.350;p>0.05\)). As depicted in Figure 6d, the finding of the overall workload in Experiment II departed from that in Experiment I.  
Discussion: Compared to Tele-Assistance3, Tele-Operation permitted the novice to complete the collaborative task in less time and with fewer errors, but a greater number of operations. These observations were similar to those in Experiment I when comparing between Tele-Operation and Tele-Assistnce7. However, the expert had the ability of overriding the novice's operations under Tele-Assistance3. The same ability was absent under Tele-Assistance7. It seemed that this ability did not affect the capabilities of both expert and novice in maneuvering the manipulator object while performing the collaborative task. Interestingly, there was no significant difference of the overall workload perceived by the novice under Tele-Operation and Tele-Assistance3. The novice followed the commands directed by the expert under Tele-Operation, whereas he/she had to do more under Tele-Assistance3 in terms of interpreting the intentions of the expert, devising accordingly his/her own plan of operations, and executing the plan. The overriding ability of the expert reduced the novice's degree of autonomy. This might have prevented the novice from taking his/her responsibility seriously in terms to the perceived need to ensure the success of his/her operations. Consequently, the novice perceived the overall workload under Tele-Assistance3 to be the same as under Tele-Operation.