Comparing Representations of Contribution Labels in Goal Models

Goal models have been proposed to be an effective method to support decision making in early requirements engineering. Key to using them is the concept of contribution links that represent how the satisfaction of one goal affects that of another. Multiple proposals have been offered for representing contribution; however, the degree to which users can intuitively understand the meaning behind contribution representations and utilize them appropriately has not been thoroughly studied. This work reports the results of an experimental study that compares the intuitiveness of two contribution representation approaches by measuring the performance of untrained users and exploring the role of individual differences (cognitive styles and arithmetic attitude and ability) in establishing the right intuition. Results show significant differences between the two representations as well as effects of various levels of individual factors. The results inspire further research on contribution links and support the operationalizability of intuitiveness as a criterion for evaluating conceptual modelling language designs.