Table 7.

Continued device use Kendall τb correlation for each usability question.

Question number	Question	Rank	P value
10	The activity tracker was comfortable to wear at night.	0.348	.003
17	Using the activity tracker helped me be more active.	0.340	.003
15	The activity tracker accurately tracked my physical activity.	0.317	.005
6	I was able to wear the device easily without help from another person.	0.308	.009
9	The activity tracker was comfortable to wear during the day.	0.306	.01
4	I think that monitoring my health 24 hours a day, 7 days a week is a good thing.	0.264	.02
5	I am comfortable with my health data being stored on the internet.	0.264	.02
13	I had no concerns about my privacy while wearing the device.	0.253	.04
2	Have you previously used a wrist-worn activity tracker before the project?	0.209	.09
14	I was happy to wear the sensor in public.	0.206	.08
8	I was able to perform my daily tasks as usual while wearing the device.	0.202	.09
18	Over the last week, how many days did you wear the device?	0.187	.12
19	Did you wear it at nighttime?	0.169	.18
16	I was happy to wear the sensor around the house.	0.164	.18
12	I was able to put on the device in a reasonable amount of time.	0.119	.31
1	Have you heard of wearable smart devices before the project?	0.115	.36
7	I was able to remove the device easily without help from another person.	0.083	.50
20	Did you remove the device during the day for reasons other than getting the device wet?	−0.078	.53
3	Did you like the appearance of the wrist-worn activity tracker?	0.054	.66
11	I was concerned that the device was not securely attached to me.	−0.019	.87