# Expectation vs. Reality: Attitudes Towards a Socially Assistive Robot in Cardiac Rehabilitation
## 4 Results  
The perception assessment for patients was completed by 28 participants (eight participated in the long-term study, and 20 in the interviews). Answers were grouped by category, to perform the analysis for each construct defined in the questionnaire. A Mann-Whitney-Wilcoxon (MWW) test was applied to determine significant differences on each construct between groups. This test is suitable for the five-point Likert scale, as it presents minimal type I error rates and equivalent power with the 2-sample \(t\)-test [43]. Furthermore, it has been demonstrated that the MWW test provides better results for small sample sizes than the \(t\)-test [44]. Results of this test are depicted in Table 5, where the \(p\)-value corresponding to each category was computed. As Table 5 shows, in most of the constructs defined in the questionnaire, a significant difference (i.e., \(p\)-value \(<\) 0.05) was found. These categories are (Perceived Trust (PT), Ease of Use (EU), Perceived Utility (PU), and Usefulness (U)). On the other hand, Safety (S), Perceived Sociability (PS), and Social Presence (SP) do not present a significant difference between groups. The distribution of the Likert questions grouped by category is presented in Figure 5. Each category contains the results obtained from control and intervention groups. This plot is presented with a central axis, indicating a neutral position regarding the question (positive perceptions are plotted on the right side of the graph, while negative perceptions are represented on the left side). Regarding the open questions, in the long-term study, all participants showed high interest in the robot-based therapy: 100% of the participants would recommend the therapy to incoming patients. On the other hand, in the interviewed group, 75% of participants found the therapy interesting and functional, and would recommend the system for future use, whereas 25% demonstrated no interest in the application and would not recommend the therapy due to different reasons that are considered and analyzed in the discussion section. \begin{table}
\begin{tabular}{l} \hline
**Pre-Session Questionnaire** \\ \hline Acceptance \& usability based on UTAUT [18] \\ Opening Discussion \\ \hline
**Pre-Demo Discussion** \\ \hline Introduction of conventional technologies in medicine \\ Presentation of Socially Assistive Robotics \\ Motivation: how social robots can benefit therapy programs \\ \hline
**Project Demonstration** \\ \hline Demonstration of the cardiac rehabilitation SAR interface with Nao \\ \hline
**Post-Demo Discussion** \\ \hline Demo feedback \\ Suggestions and applications with potential use \\ \hline \end{tabular}
\end{table} 
Table 4: Focus group with clinicians. \begin{table}
\begin{tabular}{c c} \hline
**Construct** & **Control vs. Intervention** \\ \hline SP & 0.1612 \\ PS & 0.087 \\ PT & **0.00006** \\ EU & **0.02476** \\ S & 0.13782 \\ PU & **0.00027** \\ U & **0.00069** \\ \hline \end{tabular}
\end{table} 
Table 5: Mann–Whitney–Wilcoxon test \(p\)-values. For the clinicians, the UTAUT results are illustrated in Figure 6. Each construct represents a percentage of the total responses, taking into account the Likert scale. Although remarkable, the results regarding (U/A), (U), (PU), (PS), and (PT) categories have a positive score, and that of the (S) construct is negative, as that the question refers to the robot as a risk during CR therapies. Commentaries of the pre- and post-discussion, regarding clinicians' opinions on social robotics and the proposed interface, were recorded. Prediscussion results showed that clinicians were worried about being replaced by the robot, this was expressed in commentaries such as, _\"The robot can measure all the parameters that I usually monitor\"_ and _\"The robot can replace my work.\"_ Also doubts in the functionality and features of the interface were expressed ( _\"Why a robot? Can not be other device?\"_ and _\"Sensors could fail in the measurements and report wrong data\"_).