## 5 Proposed Interface Design Method
### Requirements Analysis  
The first step is to define the user's operational requirements. It involves understanding how the users work, the cognitive processes they employ, and identifying their information needs. This can be achieved through the SA requirements analysis using the GDTA method. As described by [PERSON], [PERSON], et al. [15], the GDTA is implemented through a series of individual unstructured or semi-structured interviews with subject matter experts (SME), considered practitioners with expertise in their fields [32]. The initial interviews aim to elicit the user's goals for successful job performance, the decisions needed to attain those goals, and the information required to make those decisions (SA requirements). The data collected from the interviews are then analyzed and mapped to build a preliminary set of relational, hierarchical diagrams that structure the goals, decisions, and information, providing insights into how practitioners process information for successful job performance. These insights are also useful for defining the system's operational requirements. To ensure completeness and accuracy, the diagrams are iteratively refined through subsequent interviews with the SMEs until a consensus is reached. The reader can consult [15; 24] for a more detailed exploration of the GDTA implementation.  
The user's goals and SA requirements elicited through the GDTA are the basic elements for designing the interface and will be used in the design conceptualization phase.  
The next step is to define the system's operational requirements. It involves translating factors such as environmental conditions (e.g., noise levels, safety requirements), user characteristics (e.g., background knowledge, languages), and other operational requirements (e.g., types of information sources), along with the user's operational requirements (previously defined in the GDTA), into characteristics and operational behavior that the system must meet.  
Figure 3: Interface design matrix structure.  
For example, field managers often work in dynamic, hazardous, and noisy environments. This context leads to several system's operational requirements: (a) the system must be portable so it can run on mobile devices (handset or headset) on the construction site; (b) the system interface must not compromise the user's awareness of their physical surroundings to prevent hazards; and (c) in noisy environments, the system must prioritize visual presentation over audio. Likewise, the SA information requirements elicited from the EDTA lead to cognitive aspects that the system must meet. For instance, a cognitive requirement is that the system must present information (level 1 SA) in a way that minimizes the user's cognitive load and directly supports the comprehension of the current situation (level 2 SA) and the projection of its future status (level 3 SA). More practical examples are provided in Section 6.1: Requirements Analysis of the Practical Application and Results section.  
Following the framework proposed by [PERSON] et al. [33], the system's operational requirements are organized into key areas, including technical environment, physical environment, system integration, portability, and maintainability. An additional area, cognitive requirements, was included to address the cognitive aspects of the SA-oriented design. Designers must consider the system's operational requirements when conceptualizing information presentation.  
Figure 4: Proposed method for designing effective SA-enabling AR/MR interfaces.