## 6 Experimental Evaluation and Discussion
The efficiency is evaluated based on the rate of overall correct repetitions and outlined in Table 2.  
The medication adherence scenario has been executed in total 84 times, out of which 68 were correctly performed, resulting in an overall accuracy of 80.95%. A repetition was marked as correct only when the robot had returned to the monitoring state, disengaged from the scenario and was aware about whether the participant had taken the medication or not. To extract this outcome, the sub-graph of the states with the adjunct actions, as inferred from the POMDP, has been compared with the external camera recordings. The remaining 16 erroneous executions concerned situations in which the robot was uncertain about whether the user had taken the medication due to errors stemming from the perception, action and communication skills' faulty operation, as well as other types of unexpected situations, all summarized in Table 3. In particular, the erroneous executions that occurred relied firstly on the localization error where--in four instances--the robot parked with the wrong orientation. Such types of errors directly influence the transformation chain, especially when it comes to the detection of objects like the \"pill box\", which requires cm level accuracy. The overall localization error of the RAMCIP robot platform is \(\pm 5\) cm lateral and \(2^{\circ}\) rotational, which is considerably low when it is compared with the requirement to position the RGB-D camera so as to bring the \"pill-box\" centred to the RGB-D camera FoV. However, there were certain situations in which aggregated localization error \begin{table}
\begin{tabular}{c c c c} \hline \hline
**No. Participants** & **No. Total** & **No. Successful** & **Overall** \\  & **Repetitions** & **Executions** & **Performance (\%)** \\ \hline ine 12 & 84 & 68 & **80.95** \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Overall evaluation results on the assistance provision in the medication adherence scenario. Figure 14: Selected cases of execution of the medication assistance scenario in 12 different real house environments.The instances concern RAMCIP robot during “pill box” grasping from high shelf (**first row**), activity monitoring (**second row**), “pill box” grasping from table (**third row**) and “pill box” release to its storage position (**last row**). led to robot parking poses that severally influenced the object detection algorithm and, thus, the grasping of the \"pill box\". The robot was unable to recover from this situations by utilizing its internal mitigation strategies, and the scenario was terminated. Human activity recognition is also a very challenging task in uncontrolled environments and, as expected, affected the outcome of the evaluation. There were three situations where the robot did not recognize correctly the outcome of the activity tracking. This phenomenon has been observed in situations where skeletal occlusions were excessive or the illumination reflections severally influenced the data from the depth sensor. As a result, the joints of the participant either were not observable at all, or the existing skeleton topology was an outlier, hence the skeletal joints did not comply to any geometric criteria that were posed. In those situations, the robot either accidentally spotted that the user had taken the medication and terminated the assistive scenario or prompted the user to take the medication, even if s/he had already done it. Arm manipulation and grasp planning also comprised significant challenges during the deployment in the diverse environment of the participants' houses. In more detail, four (4) planning errors occurred during the experiments, two of which concerned the arm trajectory generation and two concerned the grasp planning. Considering the arm trajectory generation, the problematic situations were spotted in very tight environments where the workspace was very limited due to surrounding objects/furniture.