## 4 Discussion
### Limitations  
While we assume that our study provides promising insights about the UX of our system, it does have several limitations, which are discussed in the following. The younger participants of session 2 completed the questionnaires mostly by themselves. Only one question was raised about the interpretation of an SUS item; a research team member answered it neutrally. However, all participants of sessions 1 and 3 received help with the questionnaires. Care was taken to use neutral language when explaining questions and answer options, so as not to create a bias among the participants. Nevertheless, this approach may have had an impact on the results--for example, as a result of sympathy or antipathy towards the researchers. In addition, social desirability bias might have played a role. [PERSON] and [PERSON] describe in [46] that participants often show a tendency towards better ratings, as they assume these are desired by the interviewer. Additionally, in session 3, we noted that completing the SUS items of our questionnaire seemed challenging to the participants. For several items, the participants seemed unsure how to answer and required an explanation. While completing the SUS items, one participant even commented on their tendency to select the neutral option.  
After session 1, we optimized the system and implemented various changes, which were only tested with experienced chatbot and/or robot users in sessions 2 and 3. In the future, we will also test the optimized version with users who have none or only a little experience with robots. Additionally, the internet connection in session 3 may have had an impact on the reported UX of the participants, as it led to difficulties and delays in the robot's speech recognition. In the future, we will conduct this test again with a user group with extensive Pepper experience and an optimally working internet connection.  
In this study, we conducted single tests, so each participant used the system only once. Such a limited test duration does not allow any conclusions to be drawn about the long-term use of the system. Furthermore, sessions 1 and 2 were conducted with a number of participants generally deemed as adequate for testing UX [44]. However, even when taking into account the reduced population the samples were drawn from, the sample sizes are too small for valid statistical analysis. Nevertheless, we chose to use validated UX questionnaires, as we felt that the questionnaires explore our target figures, i.e., UX and usability, in full. While we are aware that our results are not statistically significant, they provide a promising indication of our system's UX. We also included only one caregiver in session 1, and the user group in session 2 consisted of members of our lab as a convenience sample to confirm that our system works correctly and to evaluate the usability of our system among expert users. Additionally, due to the direct effects of the current pandemic situation, we were able to include three participants in session 3 only. While this number of test users and the inclusion of a convenience sample cannot provide significant and transferable results, the feedback from all user groups was nevertheless very valuable as a first indication and resulting implications for future work.