*5.4. Acceptability*

In Figure 10 we present the results of the acceptability portion of the post-study questionnaire. It is worth noting that the study subjects' acceptability of this technology is lower than the acceptability reported in other telemonitoring applications such as in congestive heart failure (CHF) [46,47]. This can be attributed to multiple factors. First, some subjects voiced preference for using a monitoring device with a smaller form factor than a smartphone for this application. For example, one subject stated: "I'm a big fan of using running watches instead of phone apps because the form factor is much more comfortable. That's the main reason I was so negative about using a phone-based athletic trainer". In that regard, we note that the Berkeley Telemonitoring framework supports general Android devices, not only Android smartphones. Therefore, an Android smart watch application can be implemented using the same framework, averting the form factor challenge. Second, people may be more likely to tolerate certain drawbacks in a technology if they perceive a higher utility and value in it. As such, the higher levels of acceptability in CHF telemonitoring and intervention (e.g., [46]) may be attributed to the potentially higher perceived utility and value of the technology to the subjects in that application [47].

**Figure 10.** The results from the acceptability portion of the post-study questionnaire (*N* = 6). SD = "strongly disagree", D = "disagree", N = "neutral", A = "agree" and SA ="strongly agree" [47].

Another aspect of the post-study questionnaire focused on the privacy aspects of the technology, as perceived by the subjects. In that portion of the questionnaire, the subjects were asked the following set of questions. "Sometimes the smartphone might automatically record, or ask you to report, specific kinds of information about your health or behavior, such as your weight, your mood, or your blood pressure. The following questions will help us understand how comfortable you are with the idea of other people knowing these things about you". In Figure 11 we present the subjects' responses indicating their levels of comfort in sharing data about their (i) weight; (ii) level of physical activity; (iii) exact physical location at any point in time; (iv) heart-beat rate; (v) types of physical activity they do; and (vi) mood at any point in time, with: (i) doctors and nurses who provide them healthcare; (ii) researchers who study athletic training technology; (iii) public health professionals who study the effects of exercise and athleticism; (iv) insurance companies that set their health insurance prices; and (v) close family members who care about their health [47].

In particular, the data provide an indication that the subjects' level of comfort in sharing data about their fitness, GPS, health and mood with technology researchers is comparable to sharing those variables with their family and physicians [47]. In contrast, the subjects were noticeably less comfortable sharing these variables with their health insurance companies, suggesting that they are not privacy indifferent. These two observations combined suggest that the provided technology is at an acceptable level from a privacy point of view. In addition to the ethical reasons for designing privacy-aware data-collection systems, these findings are of great significance because they have direct implications on the adoption of these systems [39].

We note that the privacy acceptability levels are similarly high to those reported in the other applications such as CHF [46,47].

**Figure 11.** The responses to the privacy portion of the post-study questionnaire about the subjects' comfort levels sharing different data variables with different parties (*N* = 6) [47].
