Hybrid Crowdsensing: A Novel Paradigm to Combine the Strengths of Opportunistic and Participatory Crowdsensing

Crowdsensing systems can be either participatory or oppor- tunistic, depending on whether the user intentionally con- tributes data, or she simply acts as the bearer of a sens- ing device from which data is transparently collected. In this paper, we propose hybrid crowdsensing, a social media- based paradigm which aims at combining the strengths of both participatory and opportunistic crowdsensing. With hybrid crowdsensing, possibly relevant data is collected via an opportunistic approach. Then, users that spontaneously contributed are directly contacted and asked to provide ad- ditional information following a participatory approach. To demonstrate its feasibility and usefulness, we experimented the proposed paradigm for involving Twitter users in an emergency relief scenario. For each of the two real-world experiments we analyze the answer ratio to our questions, their time distribution, and responders’ willingness to col- laborate. Results support the adoption of hybrid crowdsens- ing, especially in those practical scenarios where users are emotionally involved.