## 4 A Case Study Using PEL
### Authoring Tool Evaluation with Therapists
#### 4.2.1 Questionnaire Design  
The questionnaire was designed using Microsoft OneDrive Forms both to include multimedia content and facilitate their digital processing. It was divided into two sections:  
* **System demonstration**. A demonstrative video for about 3 min was included to explain the features and functionalities of the system.
* **Evaluation of the system**. A set of questions were included with different objectives. Some of them were designed so that they provided valuable information that enable continuously improving the system and how PEL can be adapted to address such improvements. Others were added to measure certain aspects of the system.  
The second section of the questionnaire was followed using the Goal-Question-Metrics. Firstly, therapists were asked if they knew virtual rehabilitation systems. In this way, we can study the referred systems in order to improve ours. Secondly, they were asked to indicate which group of people could benefit most from the system. Next, a question was introduced for obtaining feedback from therapists to know what information should be collected when a patient finishes an exercise. Subsequently, they had to select with what frequency they would like to receive the information generated by the system after a patient has performed a rehabilitation activity. Subsequently, they were asked to complete a total of 15 questions (see Table A2 in Appendix B), scored with a Likert scale (1: totally disagree; 5: totally agree) grouped in three dimensions: TAM framework, system perception, and game elements.  
* **TAM**. The first dimension consists of questions to measure the perception of system usability (PEU), perception of usefulness (PU), and intention of use (ITU).
* **System perception**. The second dimension is composed of a set of questions to evaluate the motivation that the system can produce in the patient (MOT), the constancy the system can generate in old people (CONST), if the system can improve the rehabilitation process in a rehab center (IMP1), and whether it would improve the rehabilitation process at home (IMP2).  
\begin{table}
\begin{tabular}{l c c c c c c c c c c c c c} \hline \hline  & E1 & INT2 & EFF & GE1 & GE2 & GE3 & GE4 & GE5 & GE6 & GAM & PU & ITU1 & ITU2 & PREF & CONS & PSA \\ \hline TD & 0.82 & & & & & & & & & & & & & \\ E1 & & & & 0.53 & & 0.49 & & & & & & & & \\ E2 & & 0.55 & & & & & & & & & & & & \\ DD & & & & & & & & & & & & & & \\ EF & & & & 0.72 & 0.62 & & & & & & & & & \\ GE2 & & & & 0.85 & & & & & & & & & & \\ GE4 & & & & & & & & & & & & & & \\ GE5 & & & 0.56 & & & & & & & & & & & \\ G6 & & & 0.36 & & & & & & & & & & & \\ INT1 & 0.67 & & 0.47 & & & 0.44 & 0.30 & & & & & & & & \\ INT2 & & & & & & & & & & & & & & & \\ PREF & & & & & & & & & & & & & & & \\ PU & & & & & & & & & & & & & & & \\ ITU1 & & & & & & & & & & & & & & & \\ ITU2 & & & & & & & & & & & & & & & \\ CONS & & & & & & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 2: [PERSON]’s rank correlation coefficient. Significant values (\(p\)-value \(<\) 0.05) are marked in bold.  
* **Game elements**. The third dimension consists of several questions to measure the adequacy of the user interface from the therapists' perspective.  
Once the therapists completed the part of the questionnaire based on Likert scale questions, they could provide some comments about the system. For example, potential actions the system could perform and their advantages to strengthen them in the near future.