Citizen science has rapidly spread in the last decades around the world as a genuine interactive and inclusive opportunity for engaging citizens in the continuous collection of data relevant for science, governance, businesses, communal living and individual concerns. The present–day abundance of ICT technologies has caused the proliferation of two data collection methods in this field: participatory (user-centric) and opportunistic (device-centric). As a result, citizen observatories have become big data systems, with large scale volumes of data that come and go to millions of users.; about any social or environmental phenomenon (e.g. transit, air or weather) and comes in different formats (e.g. XML, Plain Text, CSV) and through different platforms (e.g. websites, mobile apps, sensor networks).
This study reviewed the last 10 years of citizen science literature through a systematic literature review. This study identified 108 citizen observatories, which were deeply studied and clustered to identify global and European trends in environmental applications, practices, engagement techniques and technology uses. Challenges and recommendations from the literature in the field were classified to understand the common present and future path for the discipline. Furthermore, a survey and interviews were applied to stakeholders in Finland to gain broader understanding of the field country–wise. This study, provides the first comprehensive insight of the broad scale of contemporary ICT enabled citizen observatories in social and environmental dimensions.