## 4 Results and Discussion  
From the analysis of the game results, it has been possible to deduce that all three objectives discussed in Section 3.5 have been met. With respect to the first objective, the MARISA Game allowed the collection of the players' belief assessments for the different knowledge structures. Those beliefs have been mapped to subjective probabilities (Section 3.4) and used to populate the MSDBN. As an example of such process, we can consider Figure 8. It shows four different configurations of the same knowledge structures included in a knowledge card of the Smuggling of Goods (SMG) Island card deck and the corresponding belief stated by a player during EXP2 (Section 3.5). For this example, we have the following three variables:  
1. _Q_: _Compatible with SMG: vessel characteristics_;
2. \(D\)1: _Compatible with SMG: vessel type;
3. \(D\)2: _Compatible with SMG: vessel size_. The resulting subjective probabilities are:  
\[p(Q=True|D_{1}=True;D_{2}=True)=0.825 p(Q=False|D_{1}=True;D_{2}=True)=0.175,\] \[p(Q=True|D_{1}=True;D_{2}=False)=0.525 p(Q=False|D_{1}=True;D_{2}=False)=0.475,\] \[p(Q=True|D_{1}=False;D_{2}=True)=0.350 p(Q=False|D_{1}=False;D_{2}=True)=0.650,\] \[p(Q=True|D_{1}=False;D_{2}=False)=0.100 p(Q=False|D_{1}=False;D_{2}=False)=0.900.\] \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Feature** & **Specification** & **EXP1** & **EXP2** \\ \hline Participants & Number (n) & 4 & 5 \\ Gender & Male & 75\% & 100\% \\  & Female & 25\% & 0\% \\ Age & Average & 34.3 years & 49.8 years \\  & Standard Dev. & 5.4 years & 16.3 years \\ Status & Law enforcement / military & 75\% & 80\% \\  & Civilian & 25\% & 20\% \\ Nationality & Italian & 0\% & 100\% \\  & Spanish & 100\% & 0\% \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Participants demographics and characteristics. Figure 7: MARISA Game session with the Italian Navy. Therefore, the complete CPT for the _Compatible with SMG: vessel characteristics_ variable of the MSDBN is summarized in Table 5. The mapping has been performed for all the collected data, leading to the definition of the CPTs of the full MSDBN. With respect to the second objective, the use of the game allowed to verify and then validate the MSDBN structure. In fact, already in the playtest phase, the game proved to be an effective verification method, as a player highlighted some wrong MSDBN design assumptions. These assumptions have been removed in the final MSDBN structure, which has been presented in the two experiments. The presentation of knowledge cards acted as an inject, naturally stimulating discussions and substituting the questions of structured interview approaches. The generated discussions and consequent feedback showed that the proposed MSDBN structure is appropriate. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Compatible with SMG: Vessel Type** & \multicolumn{2}{c}{_True_} & \multicolumn{2}{c}{_False_} \\
**Compatible with SMG: Vessel Size** & _True_ & _False_ & _True_ & _False_ \\ \hline _True_ & 0.825 & 0.525 & 0.35 & 0.1 \\ _False_ & 0.175 & 0.475 & 0.65 & 0.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Conditional probability table of the query variable _Compatible with smuggling of goods : vessel characteristics_ for the Ionian Sea experiment. Figure 8: Examples of different configurations of the same knowledge structure. The experiment results positively support the game validation objective. In fact, the two experiments showed that the game overall was well perceived and, after a short explanation of the rules, players started playing confidently, without major support from the facilitator. This allowed the facilitator to focus on the discussion and collection of verbal feedback. During those discussions, qualitative (i.e., network structure) and quantitative aspects related to the MSDBN have been analyzed in depth.