## 2 Materials and Methods
### Extracting the Influencing Factors Using a Literature Review
#### 2.3.2 Extracting the Influencing Factors from the Reference Papers
Decide the organization method. The methods available to organize the findings include a bottom-up approach, where similar findings are combined until they form separate clusters, and a top-down approach, where the number of defined groups is specified first and the findings are assigned to one of the groups. We combined both approaches by referring to a model, selecting a few groups beforehand, and then adding new groups as needed. We were influenced by the conceptual model for organizing team decision-making, which consists of 5 elements: situational, decision-making, team,  
Figure 3: Method used to extract the influencing factors from the reference papers. individual, and organizational element [33]. We agreed that individual and team elements should be included since the findings could be distinctly distinguished between them. Then, there were findings about the communication between team members; thus, we need a communication element similar to the representation of the decision-making element in [33]'s model. Some findings pointed at communication as part of or as a means to perform a task; thus, we added an NPP task factor. Lastly, the surrounding environment proved to have influences on team communication; thus, we added an external factor equal to the combination of situational elements and organization elements in [33]'s model. Thus, we decided on 5 elements: individual, team, communication, NPP tasks, and external elements. Transform the finding categories into sub-elements. We assigned each category to one of the five elements, and it became a \"sub-element\". Most of the categories could be assigned into the elements smoothly. For example, \"cognitive functions\", \"communication intention\", and \"non-technical skills\" were assigned to individual elements because they are related to an individual's functions. However, some categories became unsuitable to be assigned to any element. For example, the category \"communication model\", which contained findings from [44; 45; 46], could not be assigned to any element since it covered the entire communication process. In this case, we divided the findings and assigned each of them to a suitable sub-element. Hence, the communication model in [45] was divided into \"message encoding and message decoding\", \"decision-making\", and \"situation awareness\". The first item was added to the \"cognitive functions\" sub-element, and the other two were added to the \"non-technical skills\" sub-element. We deleted 4 categories, scattered the contents of 3 categories, and removed 1 category entirely (\"communication issues/phenomena\"), reducing the number of findings from 142 to 113 findings. Sometimes, while distributing the findings of a no-longer-valid category, a suitable sub-element did exist; thus, we created a new sub-element. For example, after deleting the \"team model\", the team decision-making model from [33] had to be assigned to another sub-element. After the analysis, we distributed the contents into several sub-elements; however, we could not find any sub-element to cover contents such as \"the difference in team members' expertise level\" and \"experience in same or similar situations\". Thus, a new sub-element, \"technical skills\", under the individual elements, was created. In the end, we kept 13 of the original 17 categories, assigned them to an element (they became sub-elements), and added 5 new sub-elements, resulting in a total of 18 sub-elements across 5 elements. Define the influencing factors. We revisited the explanation of the findings to transform them into the final form of influencing factors. During this transformation, we maintained our goal of collecting influencing factors that are practical to NPP emergencies; thus, we avoided ambiguous terms and kept a similar level of information. In Table 2, we present the types of transformations from findings to influencing factors and their examples. As a result, we extracted 223 influencing factors distributed into 18 sub-elements.