# Design, Implementation, and Field Testing
## 5 Field Study
### Usability Survey Result
Question 7 is: \"Do you think this system would be helpful when first learning good body mechanics?\" For this question, only one participant indicated that PACTS is not much useful for first learning good body mechanics. Five expressed that the system is a great help in learning good body mechanics. Question 8 is: \"Do you think that using the smart watch/Kinect system resulted in any changes in your using correct body mechanics during your job tasks?\" Only two participants expressed negative opinions. One indicated that \"not so much\" and the other one believed that it did not help at all. Five participants (62.5%) have positive opinions. Two of them believed that the system helped them very much, and three said that the system helped them somewhat. Question 9 is: \"Was the vibration a good way to be notified when you were doing something incorrectly?\" This question is rather similar to question 6, but the opinion is slightly less enthusiastic with one indicating that vibration is not at all a good way to be notified. The other six participants are positive about the alert delivery method (five very positive, and one somewhat). Question 10 is: \"Did the watch ever vibrate when you thought you were moving correctly?\" All seven participants reported that they have experienced false positives from our system. Four of them indicated that this occurs very often. This shows that it is challenging to design the activity detection algorithm that works in a crowded room with unpredictable orientation of the user. We plan to enhance our current algorithm with a machine-learning based approach [9; 41; 42; 43; 44] by utilizing all joints in the upper extremity. Question 11 is: \"If so, was this a problem for you?\" This question is a continuation of question 10 and is relevant to all seven participants. Four participants expressed that the false positive is a problem for them. This shows that it is urgent to develop a better activity detection algorithm that minimize false positives. Question 12 is: \"Did you ever feel like you were doing incorrect movements without any feedback (vibration) from the smartwatch?\" This question is about false negatives of our system. Five indicated that sometimes they experience false negatives. Again, this exposed that our system needs improvement. Question 13 is: \"Did you mind having the Kinect camera record your body positions while doing bedside care activities?\" All seven participants indicated that they do not mind having the Kinect sensor record their body positions. This confirms the acceptability of FACTS by nursing assistants. As can been from the survey result, all seven participants are very supportive in using FACTS to improve their body mechanics. The survey does confirm our observation during the field test that there are several major areas that need to be improved, particularly the manual registration and the non-compliance activity detection accuracy. The comments left by the participants are overwhelmingly positive. A few example comments are listed below:  
* \"It helps me to realize how I can hurt myself by moving residents wrong to transfer a resident\". * \"I think it would be a good idea\". * \"I think it should be repeated once it's working properly. It would be a great source for proper body mechanics\". * \"It was a good experience\". * \"It was nice to participate\". * \"I enjoyed the opportunity but it needs a little fixing\". * \"Thanks for thinking of ways to keep us safe\". * \"It was different and I enjoyed it\". **6. Conclusions and Future Work**  
In this paper, we presented the design, implementation, the result and lessons learned from a field study of FACTS. The current version of FACTS has mechanisms to support the deployment of the system into multiple rooms and can continuously track multiple nursing assistants while they go to different rooms during the same shift. Furthermore, the registration gesture recognition and non-compliant activity detection algorithm is robust again occlusions typically found in nursing homes.