Ahab’s legs in scenario-based requirements validation: An experiment to study communication mistakes

The correct identification of requirements is a crucial step for the implementation of a satisfactory software system. In the validation of \edit{requirements with scenarios}, a straightforward communication is central to obtain a good participation from stakeholders. Technical specifications are translated into scenarios to make them concrete and easy to understand for non-technical users, and contextual details are added to encourage user engagement. However, additional contextual details (Ahab's Legs) could generate a negative impact on the requirements' validation by leading to proliferating comments that are not pertinent to session objective. The objective of this study is to evaluate the impact of Ahab's Leg to scenario-based requirement validation sessions. We conducted a controlled experiment with human participants and measured the pertinence of the comments formulated by participants when discussing the requirements. The results of our experiment suggest that the potentially negative impact of Ahab's Leg can be effectively controlled by the analyst.