Formal Modelling of Salience and Cognitive Load

Well-designed interfaces use procedural and sensory cues to increase the salience of appropriate actions and intentions. However, empirical studies suggest that cognitive load can influence the strength of procedural and sensory cues. We formalise the relationship between salience and cognitive load revealed by empirical data. We add these rules to our abstract cognitive architecture developed for the verification of usability properties. The interface of a fire engine dispatch task used in the empirical studies is then formally verified to assess the salience and load rules. Finally, we discuss how the formal modelling and verification suggests further refinements of the rules derived from the informal analysis of empirical data.