Refining User Stories via Example Mapping: An Empirical Investigation

Abstract

New techniques for managing, specifying, and analyzing requirements in software engineering projects are frequently presented by consultants and agile trainers. However, the effectiveness of these techniques is not evaluated in a rigorous manner, leaving practitioners with the question “Will it work in our company?” In this paper, we investigate the performance of a user story refinement technique named Example Mapping (EM). This is a time-boxed workshop in which people from different disciplines work collaboratively in order to refine, or clarify, a user story with the use of examples. The creation of such examples is intended not only to obtain a more precise specification, but also and mostly to achieve shared understanding on the user story to develop among the team members. We investigate the performance of EM via two longitudinal case studies. To enable a rigorous validation of EM, we first define the Refinement Evaluation Tool (RET), a survey-based measurement instrument that extends the Method Evaluation Model with questions that cover the shared understanding dimension. The results from our case studies show that EM contributes to the shared understanding within a team; certain conditions are necessary: the user stories should not be too small-sized. We also investigated the learning effect for EM; our data indicates that two sessions are generally necessary for the team members to use the technique effectively.