Effectiveness and efficiency as conflicting requirements in designing emergency mission reporting

Aspects of usability, such as effectiveness and efficiency, are critical for users ' overall experience of an interactive system. In response to the on-going debate on the relationship between different aspects of usability in usability studies, we present an example of a User Interface (UI) design case where the relationship between effectiveness and efficiency should be considered as a requirement or design issue, rather than as variables in usability studies. In the presented case- status reporting from an in-vehicle support system for emergency missions-these aspects of usability were perceived as conflicting rather than as positively correlated. We present various design solutions to the task of status reporting and show how the solutions support effectiveness and efficiency in different ways. Finally, we point out some characteristics of the case that could explain our findings and we suggest how future research may obtain more insight into which types of applications that may possess similar properties. Author Keywords Emergency response, usability, effectiveness, efficiency