Brainstorming versus a Scenario-based Approach: Results of an Empirical Study

Although important advances have been made to improve the requirements elicitation process, this problem is still a challenging research topic for the Requirements Engineering community. Motivated by this fact, we propose the CREAS method (Creative Requirements Elicitation Assisted by Scenarios), an approach for requirements elicitation that leverages and brings together scenario-based and creativity techniques. In this paper, we seek to answer the following research question: Does CREAS have a better impact on the elicitation of requirements with respect to a Brainstorming process? To answer this question, we have designed and run a quasi-experiment to compare CREAS and Brainstorming under similar conditions. The participants were required to elicit the requirements for two different problems in two different sessions using both approaches. Results evidence the existence of significant differences between the methods. The statistical outcomes show that the requirements obtained with CREAS are more complete, precise and present less over-specification.