Carl Westin

5-3 Ecological displays in ATC CD&R 95 5-3-2 Transparency evaluation of the SSD Evaluation of the two SSD representations was considered in relation to the dif- ferent theoretical models of transparency reviewed earlier. Brown’s 204 three trans- parency criteria were determined useful for guiding this evaluation. In contrast, the SAT framework 200 was discarded as it specifically addresses autonomous agents and their activity. Transparency pertinent to Wang and Benbasat’s 209 three explana- tions categories of recommender systems were also not considered as they specif- ically address advisories. However, why and how transparency was instead partly addressed by the conformance of advisories, with conformal solutions representing the participant’s preferred way of solving the conflict. Table 5-1 details how the two SSD representations relate to the three trans- parency criteria suggested by Brown. 204 In the context of CD&R, domain trans- parency can be considered to encompass the meta-information of the airspace and all traffic, its constraints and boundaries, that controllers use to solve conflicts. In- ternal transparency addresses the underlying reasoning of the decision support in- terface, which here relates to the algorithms underlying the visualization of intruder aircraft’s relative position. Embedding transparency reflects the mapping between interactions with the interface translates to the reciprocal interactions in the real world. For example, an avoidance maneuver implemented based on the SSD should be accurately reflected in the real world. Overall, the HB SSD was identified to afford less domain transparency in that the meaningful relationships between controlled and intruder aircraft were not re- flected adequately in no-go zones. Similarly, feedback from participants in a pre- vious study using the HB SSD indicated that interpreting the position of intruder aircraft was complicated by the small, narrow, poorly contrasted, and overlapping no-go zones. 101 Several of the issues identified for the HB SSD are addressed by the TRI SSD, which is considered to better facilitate domain transparency. 217 This is mainly attributed to the visualization of the controlled aircraft’s entire speed en- velope which improves understanding of the constraints and boundaries of intruder aircraft and how to avoid them. The TRI SSD was found to facilitate slightly more internal transparency be- cause the triangles reflect more information relevant to how the no-go zones have been calculated. As noted by Helldin, 191 internal transparency is often best facili- tated during initial familiarization and training with the interface. Finally, the two SSD representations were found to not differ in terms of embedding transparency as both are integrated directly with the primary information (radar) display. As such, interacting with the interface closely mirrors the interactions of the real world.