Skip to main content
Technology & Science


ACTION was a three-year programme funded through the European Union’s Horizon 2020 framework, led by King’s College London, UK, dedicated to transforming the way we do citizen science (CS) today: from a mostly scientist-led process to a more participatory, inclusive, citizen-led one, which acknowledges the diversity of the CS landscape and of the challenges CS teams have to meet as their project evolves.

ACTION applied a citizen science approach to tackling pollution; one of the greatest threats to human health and wellbeing of our times, killing more people than smoking, hunger, natural disasters, war and infectious diseases such as HIV/AIDS and coronavirus. We partnered with 5 European CS initiatives tackling major forms of pollution, which pose substantial threats to human health and to the environment, and contributing to Sustainable Development Goals. These pilots were subsequently joined by additional pilots recruited through our open calls; six pilots joined us in 2019, and a further 4 in 2020. Together, the pilots formed a ‘citizen science accelerator’, giving them the funding and support they need to grow and become more sustainable.

By considering the needs of multiple stakeholders throughout the lifecycle of CS, we created methodologies, tools and guidelines to truly democratise the scientific process, allowing anyone to design and realise a CS project from the early stages of ideation to validating and publishing the results. Our research accounted for the multitude of manifestations of CS, addressing everything from small-scale, localised social issues to international research agendas. All ACTION’s outputs - infrastructure, the citizen science platform and toolkit - are openly available. Our digital infrastructure helps citizen scientists use existing specialised platforms and publish results according to RRI principles, including open science. Our toolkit tackles common difficulties around methodological choices, quality, incentives, community building and sustainability. The pilots hosted by the accelerator resulted in case studies that demonstrate the impacts of CS at social, economic, environmental and policy level.

Participatory Science Lifecycle


The main objectives of ACTION were:

  • set up a citizen science accelerator to support hands-on citizen science activities to combat and prevent major forms of pollution in the EU;
  • carry out an open call to select 10 additional pilots with interesting, impactful ideas that address pressing pollution challenges not yet covered through the consortium;
  • co-design and co-develop methodologies, tools and guidelines to understand the requirements of different stakeholder groups in the citizen science lifecycle, and to open the entire scientific process to new demographic groups and communities;
  • create a digital infrastructure to help citizen scientists easily set up and manage projects in all their online and offline manifestations, manage and share their data openly, and comply withRRI (Responsible Research and Innovation) practices;
  • create a sociotechnical toolkit that solves challenges around methodological decisions, task design, quality and validation, building and nurturing a community, incentivising participation, impact, and sustainability, with a special focus on less explored types of projects, covering a range of project activities, and acknowledging the evolution of projects in time;
  • devise methods and models to assess the sustainability and impact of citizen science projects and to analyse costs and benefits from a societal, democratic, economic, scientific and environmental point of view;
  • partner with researchers, policy makers, community groups, open data and open science activists, social enterprises and third-sector organisations to establish a multi-stakeholder ecosystem for responsible citizen science and innovation and promote ACTION and our pilots in this ecosystem to receive valuable feedback and have broad impact.


Citizen science is a way for citizens without scientific training to engage in the scientific process. Citizen scientists are most commonly involved in collecting data, for example in environmental monitoring programs, or in classifying data, on platforms such as Zooniverse. There are also examples of citizen science projects hosted by NGOs, or even being built bottom-up by citizens.

Although citizen science is quite pervasive in the UK - both DEFRA and UKRI support citizen science projects - citizen science as a data collection methodology is often overlooked in most data-related legislation. Where legislation exists, citizen science initiatives are not well equipped to apply it. Given their often low capacity, they struggle as it is, and GDPR can be heavy handed for small initiatives. While there are many resources to support SMEs in working with data and applying regulations in practice, there is not much for grassroots initiatives. Other legislation, such as the national data infrastructure, data sharing, or data ethics, do not consider citizen-generated data in its own right at all.

In order to address these issues, the ACTION project, led by King’s College London, hosted policy masterclasses to discuss the use of citizen science for sustainability, with participants from institutions and government departments across the UK, Europe, and the world.

Citizen science could provide many benefits to policy making: it can collect otherwise unavailable data, and make the pool of data that policy makers can draw upon more diverse. Simultaneously, citizen science can educate citizens about science and issues in their environment. However, using citizen science for policy is also faced with a number of challenges, such as a general lack of awareness about what it is and how it could be beneficial; a misalignment between the goals of citizen science projects and the needs of policy makers; or concerns about data quality. Citizen science is sometimes perceived as a "cheap alternative", since it works with volunteers; but citizen science also requires funding to ensure data quality, and engage citizen scientists in a meaningful way. At the masterclasses, attendees from policy and research pitched challenges to and for citizen science, such as how government agencies could be persuaded to accept citizen science generated data as evidence, or how citizen science would need to be funded in order to generate diverse, high quality data.

These masterclasses showcased just how much the different challenges to citizen science are linked. For example, more case studies of citizen science would help government agencies see the value in and adopt citizen science; but in order to generate these case studies, more, and more diverse projects would need to receive funding, not only for engagement and data collection, but also data quality assurance. While funding for citizen science is available via government resources, research councils, or foundations, the target groups for these resources are very distinct, with specific kinds of organisations benefiting from distinct funds. This makes it hard for citizen science projects to establish collaborations, as potential partners cannot tap into the same pools.

Even when projects are funded and implemented, and data is collected in a diverse way, the citizen scientists who contribute data to these projects are often excluded from making decisions about the datasets that result from their work (Gomer & Simperl, 2020). One way to address this issue is to set up data trusts that allow for the data to be controlled collectively. The ACTION team is now working with one of their pilots - Mapping Mobility - to explore how the data that is collected by citizen scientists can be controlled and used by the community in the long term.

If you want to learn more about citizen science, platforms such as EU-Citizen.Science provide a range of training and case studies. The ACTION toolkit provides guidance on best practice.

Summary of Findings

The ACTION accelerator recruited a total of 10 projects, providing them with mentoring, training and support to complete a six-month pilot project focused on a pollution challenge. These joined 6 internal citizen science projects which were part of the ACTION consortium from the beginning of the project. Our pilots addressed diverse issues from promoting composting and assessing the effectiveness of bioplastics in the CitiComPlastic project to monitoring, mapping and addressing noise pollution in the city of Barcelona in the NoiseMaps project. A full list of the ACTION pilots and further details can be found on the ACTION website. The King’s College London team were responsible for managing the recruitment and evaluation of prospective partners and carrying out negotiations and administration for the accelerator process.

In addition to the accelerator, the ACTION project focused on research and innovation designed to encourage engagement in citizen science projects and to optimise the effectiveness of project outputs through processes such as quality assurance. King’s College London were responsible for performing research into task design and motivation and incentives for participants in citizen science projects. As part of this process we developed new functionality for the Qrowdsmith and Virtual City Explorer tools included below, to facilitate using crowdsourcing platforms for research purposes.

Experiences and lessons learned from the ACTION accelerator, insights from our research and input from stakeholders engaged by ACTION fed into the ACTION toolkit. This toolkit represents to the includes guidelines, case studies and links to technology, methods and tools to support anyone in designing and managing their own citizen science project -- no matter their experience or background. The toolkit represents the culmination of the research projects gathered across the 3 years of the project and has been co-designed iteratively alongside all ACTION projects.

ACTION outputs including research deliverable reports, scientific publications and tutorial materials can be found on Zenodo. More broadly, a summary of our lessons learnt and experiences of running an accelerator for citizen science projects formed the basis for a white paper on citizen science innovation produced by ACTION pilot IGB as a final output of the project which can be found on Zenodo.


Throughout the course of ACTION, project activities have been evaluated using a thorough and purpose-built impact assessment framework covering not only the project as a whole, but also the activities and outputs of the 16 ACTION pilot projects. Overall ACTION touched on 10 of the United Nations’ 17 Sustainable Development Goals, with a particular focus on good health and wellbeing; sustainable cities and communities and responsible production and consumption.

These pilots had a significant impact on public engagement and awareness of citizen science and pollution issues: pilots engaged more than 1200 volunteers in citizen science activities and engaged over 89,000 people through public dissemination and events. ACTION activities have so far resulted in 39 peer-reviewed scientific publications with more under review. Activities have also led to significant transformative impact in terms of volunteer participants’ skills and understanding.

A significant focus of ACTION has been to ensure the long-term sustainability and continuation of citizen science activities. To date, 3 additional research grants have been provided to continue work started within ACTION, including the Impetus project which aims to scale-up and build on the open call and accelerator models developed within ACTION in a citizen science context.

A full and detailed analysis of the impact of ACTION can be seen in the ACTION impact assessment reports contained within the project Zenodo repository. These cover both the project and pilots and cover a broad set of indicators including scientific knowledge, economic and financial benefits, changes in attitude and political and environmental changes.

Additionally the KCL team developed two tools to support citizen science activities within the context of the ACTION project:

Virtual City Explorer
This tool allows you to collect data about static infrastructure items in cities, by asking contributors to explores 3D environments on a page embedded from Google Street View.

This is a crowdsourcing platform which includes gamification components, such as leader boards, badges, levels, and other functions that go beyond traditional crowdsourcing tasks. It is intended to allow you to achieve optimal engagement from contributors.

Click here to read the Participatory Science Toolkit Against Pollution report.

Project status: Completed

Principal Investigator


Project websites


Funding Body: European Commission

Amount: £254,189.05

Period: February 2020 - January 2022