Today, software ecosystems have become transparent, allowing users to submit issue reports and new feature requests to the development team. The more permeable boundaries of ecosystems provide an open culture paradigm where stakeholders, customers, developers and other user groups have the access to participate during all phases of requirement development. One example of this open culture in software ecosystems is found in work item discussions, which are aimed to improve how requirements are elicited, analyzed and validated. In this thesis, we investigate who participates in requirements discussions, identifying and focusing on emergent contributors; discussants that are not officially part of the development team or required to participate, but contribute to work item discussions. We report form a case study of online requirement discussion in IBM’s collaborative lifecycle management. We find that external contributors emerge frequently during discussions and that they mediate the clarification of requirements. Our results indicate that it is important for emergent contributors to be involved early in the requirements process, otherwise there is a negative effect on the work items’ progress. We discuss the implications of our findings for both practitioners and researchers with suggestions for future studies. / Graduate / 0984 / 0291 / 0790 / aminah.yussuf@gmail.com