Deliverable 2.1 sets out the results of the benchmarking exercise, which, amongst other objectives, also identified the obstacles that may be encountered when carrying out citizen science projects.

One such example is the technological tools used in CS projects. It is well known that, with technological advances since the late 1990s, CS has taken an improvement in quality: citizens can now submit data, participate in global projects and collaborate with researchers. Particularly for activities within the natural sciences, technological advances have contributed to the rise of initiatives such as shared nature observations and participatory environmental monitoring. From biodiversity to astronomy, from air quality to land mapping, technology has transformed citizens into genuine co-researchers.

An analysis of the 70 projects studied reveals that the majority of projects use digital equipment (27%) or ready-to-use kits (21%), often in environmental monitoring and community-based data collection projects. These are generally intended to be affordable and easy for everyone to use. However, when scaling up a project, there is a risk of failing to account for the digital divide. Indeed, marginalised groups often lack access to digital tools, internet connectivity and the training required to participate in citizen science initiatives. This lack of access can lead to exclusion from data collection and opportunities for involvement, limiting representativeness and inclusivity. The challenge lies not only in providing digital tools, but in designing inclusive technological solutions that mitigate these barriers, such as offering offline participation options, low-tech alternatives or targeted training and support; or in guiding citizens on how to use the tool and making it more accessible, for example, by providing instructions in language that is accessible to all.

Technology therefore acts as a bridge between science and society, but account must be taken of the technological gap, which varies from region to region. This depends on the type of network infrastructure available in the region, the level of digital literacy among the citizens involved, the economic situation and readiness to embrace new technologies, and the cost of the chosen technology (even open-source platforms come at a cost). It is not impossible, but in-depth study and knowledge are required to minimise the negative impact and to expand CS projects in a fair and sustainable manner across the various scaling dimensions.