Safety-Critical Mobile Systems – The RESCUER Interaction Evaluation Approach

Abstract

The infrastructure organization of large-scale events involves high safety requirements for the visitors and is a central issue for the officials in charge. To assist in dealing with this, we developed the RESCUER Mobile Crowdsourcing App, which runs on smartphones and allows the crowd to report an emergency, thereby improving the process for rescuing humans in an emergency. For the evaluation of the app, we faced the problem that people participating in a large event, such as a soccer match, are not willing to spend time on completing a long survey or interview. Also, people experiencing an emergency situation may have their cognitive capabilities affected by emotional burden, so a mobile app should be easy and intuitive to interact with. Hence, the goal of this contribution was to select and perform an on-site mobile evaluation approach that allows us to evaluate the user interaction. Two main evaluations were performed using two different versions of our application. The first evaluation took place during the FIFA World Cup 2014 and tested the app’s usability with 112 users in Brazil and in Germany. As a result of this evaluation, we found severe usability issues and gained concrete insights into how to solve them. The second, follow-up evaluation, using an improved version of our app, was performed during emergency exercises in Brazil, with 31 experts in emergency management. For our evaluation approach, the results indicated that on-site mobile evaluation is an appropriate method for improving the usability and interaction of safety-critical software systems.