Clarifying Goal Models

Representation and reasoning about information system (IS) requirements is facilitated with the use of goal models to describe the desired and undesired IS behaviors. One difficulty in goal modeling is arriving at a shared understanding of a goal model instance, mainly due to different backgrounds of the system stakeholders who participate in modeling, and the subsequent disparate use of terminology. Lack of shared understanding, or, in other words, the presence of multiple interpretations entails no guarantee that stakeholders' expectations expressed in the model instance will be appropriately understood during the subsequent steps of system development. Among the many potential causes of multiple interpretations, this paper focuses on a critical set of such causes, namely: ambiguity, overgenerality, synonymy, and vagueness of information represented in instances of goal modeling primitives. The "Goal Clarification Method" is suggested to guide the identification of unclear information and the subsequent clarification thereof.