# Explainable Post-Occupancy Evaluation Using a Humanoid Robot
## 3 Explainable POE Approach
### Data Acquisition  
As previously mentioned, the robot acquires data also from the environment and the user. The robot was equipped with wearable sensors to collect environmental data. As previously said,  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Thresholds in SUMMER**} & \multicolumn{2}{c}{**Thresholds in WINTER**} \\ \hline
**Relative Humidity** & **Low Temp** & **High Temp** & **Low Temp** & **High Temp** \\ \hline
30\% & 24 \({}^{\circ}\)C & 27 \({}^{\circ}\)C & 20 \({}^{\circ}\)C & 25 \({}^{\circ}\)C \\
60\% & 23 \({}^{\circ}\)C & 25 \({}^{\circ}\)C & 20 \({}^{\circ}\)C & 23 \({}^{\circ}\)C \\ \hline \hline \end{tabular}
\end{table}
Table 1: Comfort zones for the summer and winter seasons.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Type of Activation** & **Illuminance** \\ \hline Writing, typing, reading \(\ldots\) & 500 lx \\ Technical design & 750 lx \\ Conference and meeting & 500 lx \\ Reception & 300 lx \\ \hline \hline \end{tabular}
\end{table}
Table 2: Examples of recommended light levels for offices.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Type of Application** & **Max Noise Rating Level** \\ \hline Concert halls, broadcasting and recording studios, churches & NR 25 \\ Halls, shops cloakrooms, restaurants, night clubs, offices & NR 40 \\ Offices with business machines, typing pools & NR 50 \\ Foundries and heavy engineering works & NR 70 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Maximum recommended noise rating levels.  
the location of sensors is fundamental for the reliability of measurements. In this study, the sensors were transported by the robot, and its mobility was exploited both for taking the measures close to the user and for monitoring them in the whole space. The parameters measured by the sensors were the illuminance (lx), the indoor temperature (\({}^{\circ}\)C), the relative humidity (%), and finally, the sound pressure level (dB). To collect the environmental parameters, we used the following sensors:  
* A humidity and temperature sensor provided by the SHT31 Smart Gadget device, which is also endowed with data logging capabilities and Bluetooth Low Energy (BLE) connectivity.
* A light sensor provided by the ISO-Tech ILM350 Digital Lux Meter, which is designed to give light level readings up to 50,000 lx. It also allows light measurements away from the subject area to be collected.
* The microphone of a Huawei smartphone to obtain the sound pressure levels.  
The robot, moving close to the user, gives her/him guidelines for positioning sensors in particular locations to take the validation point measurement. For example, the above-mentioned standard EN12464 recommends having 500 lx on the desk when a user performs a read task. Hence, the robot asks for the user's collaboration in positioning the sensor at a point where (s)he reads most often. Thus, it can take one measurement in a place where permanent sensors are usually not positioned.  
Then, to acquire information about the user, the robot applies the POE questionnaire. Such a survey was designed to obtain user's feedback about his/her preferences and sense of well-being related to thermal, visual, and acoustic conditions. For example, some questions were about: (i) the thermal satisfaction (the expected answers were based on the ASHRAE seven point sensation scale [3] ranging from very satisfied to very dissatisfied); (ii) the illuminance conditions (i.e., \"Too dark, Ok, Too bright\"), and the perception of the noise in the environment.