Comparing alternative goal model visualizations for decision making
Decision making is an important part of early requirements analysis. Analysts are faced with the task of describing a large number of solutions to stakeholder problems and assess each of them with respect to high-level objectives. Goal models are regarded to be a useful tool for assisting this decision making activity through explicating relationships among problems, criteria and solutions. To visualize goal models, box-and-line diagrams have traditionally been used. But are diagrams the best way to visualize decision problems within goal models? In this paper, we consider two alternative ways: tree-maps and common pie-charts combined with bar-charts. In an experimental study we evaluate each with respect to whether they can help participants identify optimal alternatives accurately, quickly and confidently. We find that, for at least one of the introduced visualizations, participants tend to respond faster, more confidently and more accurately than when using traditional goal diagrams. The result calls for rethinking the way we visually present goal models and for further experimentation on the matter.