Towards crowd-based requirements engineering. A research preview

[Context and motivation] Stakeholders who are highly distributed form a large, heterogeneous online group, the so-called "crowd". The rise of mobile, social and cloud apps has led to a stark increase in crowd-based settings. [Question/problem] Traditional requirements engineering (RE) techniques face scalability issues and require the co-presence of stakeholders and engineers, which cannot be realized in a crowd setting. While different approaches have recently been introduced to partially automate RE in this context, a multi-method approach to (semi-)automate all RE activities is still needed. [Principal ideas/results] We propose "Crowd-based Requirements Engineering" as an approach that integrates existing elicitation and analysis techniques and fills existing gaps by introducing new concepts. It collects feedback through direct interactions and social collaboration, and by deploying mining techniques. [Contribution] This paper describes the initial state of the art of our approach, and previews our plans for further research.