Crowdsourcing

"Crowdsourcing was originally defined by Howe (2006) as the act of a company or institution taking a function once performed by employees and outsourcing it to an undefined (and generally large) network of people in the form of an open call. More specifically, crowdsourcing has traditionally been used as an outsourcing method, but it can now be considered as an approach to collecting data through the participation of the general public, therefore requiring the active involvement of citizens. However, more recently, this definition has been relaxed somewhat to also include data collected from public sensor networks, that is, opportunistic sensing and the Internet of Things, as well as from sensors installed and maintained by private citizens. In addition, with the onset of data-mining, the data do not necessarily have to be collected for the purpose for which they are ultimately used.

Crowdsourcing can be considered as an important supplementary data source, complementing traditional data collection approaches, while in some developing countries, crowdsourcing may even play the role of a traditional measuring network due to the lack of a formally established observation network (Sahithi, 2016). This can be in the form of increased spatial and temporal distribution, which is particularly relevant for natural hazard management, for example, for floods and earthquakes. Crowdsourcing methods are expected to develop rapidly in the near future with the aid of continuing developments in information technology, such as smart phones, cameras, and social media as well as in response to increasing public awareness of environment issues. In addition, the sensors used for data collection are expected to increase in reliability and stability, as will the methods for processing noisy data coming from these sensors. This in turn will further facilitate continued development and more applications of crowdsourcing methods in the future." (Zheng et al., 2018)