ACTION was a three-year programme (completed in January 2022), funded through the European Union’s Horizon 2020 framework, led by Prof Elena Simperl

ACTION was a three-year programme (completed in January 2022), funded through the European Union’s Horizon 2020 framework, led by Prof Elena Simperl 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.

Picture of ACTION programme

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.

Picture of the 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.

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.


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.

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.

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.