Starting with his own work in conservation biology, Romain Julliard built an expertise on data collection by citizens, that he help today others to implement You are a specialist in conservation biology. Why did you become interested in citizen science? Romain Julliard: For practical reasons, first. The study of changes in biodiversity as we face global changes needs to be carried out on huge time and space scales, for which we lack professional or technical observation facilities: experimental stations, or field observations that we could carry out with students, are not fit. Only networks of human volunteers can be deployed and maintained on these scales. They enable us to collect very rich data, as long as they are structured, planned and standardized. What’s more, these observers easily provide important information about their environment, their practices and their local knowledge. Starting in 2006, “Opération Papillons” (Operation Butterfly) was your first citizen science initiative for unskilled volunteers. What scientific questions did you want to answer? R. J.: The aim was to study how this group of pollinating insects cope with urbanization: which species are able to strive into the city? Why? Where? What are the characteristics of the city that make it possible or impossible for them to enter? Butterflies are representative of flying insects, and easy enough for non-specialists to identify. The network, which extends to several thousand gardens across France, in a wide variety of areas, in the city, in the suburbs and out-of-town, provides information on the organization of biodiversity at these scales, and also links observations to other information such as the landscape, the size and composition of the garden, and the practices of gardeners. Without those participants, it would be almost impossible to obtain this information. You began this type of work in the 2000s: was it innovative? R. J.: In the past, there were surveys by expert naturalists, communities and learned societies. For example, there was a long-standing tradition of collaboration between ornithologists’ associations and the Muséum National d’Histoire Naturelle (MNHN), which initially focused on mapping and species description: what is the distribution of species ecology independently of human? Gradually, we shifted our paradigm to monitoring, focusing on dynamics and human-induced changes. We have therefore also changed our methods. The completeness associated with mapping is very different in terms of statistics, from standardization and reproducibility of measurements, which are important for monitoring. To monitor biodiversity, scientists have changed both discipline and method. Then, in the mid-2000s, we introduced “general public” monitoring, which did not rely on the participants’ prior skills. Participants acquire new skills as they take part in the research, both in terms of butterfly identification and ecology: butterflies are caterpillars, there are migratory butterflies, seasonal butterflies, and so on. And these skills have consequences for species conservation, by transforming the way they keep their gardens. Have you studied this aspect? R. J.: One of the promises of participatory science is the transformative power it can have on individuals, and even on the collective of individuals who take part in research. A colleague carried out a survey of the members of our partners in biodiversity monitoring, large associations. Among the respondents, half were not involved in monitoring. He showed that these had a slightly higher average level of education than the one who were participating. On the other hand, among the latter, the average level of confidence in science was higher. But we don’t know whether the higher level of confidence was due to participation in the project or whether it was the cause. Can participatory science have a wider impact? R. J.: There is a social legitimacy effect for scientific results produced in this way. If we announce: “there has been a 30% decline in common bird populations, a network of thousands of observers working with the Museum has produced this data”, social acceptability is greater than if the result were obtained from the observations of a few research stations. Even if, scientifically, both results are equally valid. Did your scientific colleagues take this participatory approach for granted? R. J.: There was a lot of resistance. This type of research changes the position of power in relation to the objects studied: scientists are no longer the exclusive masters of research. There is a sharing of responsibility and power, as well as a dependence, between the network of data producers and the researchers. And there’s also a constraint, linked to the commitment the scientists make to the network members to valorize these data. There was considerable reluctance from some researchers who were not involved in participatory science, who saw it as a threat to their profession. Today, few researchers express this reluctance. However, we still meet strong opposition in the technical professions. For example, I am having trouble convincing members of agricultural technical institutes to carry out participatory research projects with large network of farmers to study the transitions underway. Many of those who work there prefer to keep a dominant position vis-à-vis those they advise. Yet it seems fairly obvious that, by conducting participatory research involving farmers, foresters, planners or architects, the knowledge produced will be shared directly with those most likely to apply it. So, the impact is greater? Especially in terms of speed of transmission. In the current model, scientists carry out research, they produce knowledge that will enlighten society, which is then responsible for using it to develop policies and so on. It’s a slow process, compared to the transition and transformation challenges we face today. This is one of the reasons why so much attention is being paid to citizen and participatory science. We think that this approach is well-suited to the challenge of rapidly finding solutions to these changes. What is behind the current slow pace? R. J.: There is a time lag: the problems we study in research are already out of date by the time they reach the stage of possible implementation. And there is a problem of relevance: researchers tend to study what interests them,

“A kind of scientific knowledge production in which people from civil society participate actively and deliberately”: this definition of participatory science guides Fabian Docagne to develop science and society synergies. Fabian Docagne is director of research at France’s Institut National de la Santé et de la Recherche Médicale (INSERM), and head of the institute’s Science and Society service What does citizen participation in research mean for INSERM? Fabian Docagne: Over the past 20 years or so, INSERM has forged links with patient associations. The institute was a pioneer in France. Following a national trend, driven in particular by the 2020 “Loi de programmation de la recherche” (research national programming law), INSERM has included the implementation of participatory research in its 2025 strategic plan. From the “Charte des sciences et recherches participatives en France”, published in 2017, participatory research is “a kind of scientific knowledge production in which people from civil society participate actively and deliberately”. The aim is to promote the expertise that comes from experience and to make it complementary to academic knowledge. It means giving a voice to this experiential knowledge, owned by the people concerned in the broadest sense: patients, their families and carers, as well as healthcare professionals, paramedical and social professionals, and others. All those who are involved in healthcare, and who may have an opinion to offer. Beyond meeting legal requirements, what are INSERM’s core motivations for developing participatory research? F. D.: There is the will to have a science that is more in touch with, and responsive to, society. Firstly, participatory science contributes to a better perception of the scientific process. The Covid crisis showed that a certain segment of the population mistrusts scientists. But on the positive side, it has triggered a huge curiosity in society about what science is doing. Participatory research is a way of responding to both this mistrust and this curiosity. Secondly, it allows us to generate new questions and answers that are better adapted to society’s needs. This is linked to the production of better-quality science: methodologies are co-constructed with the people concerned, they are more adapted, and so we produce better-quality data. How is this implemented as concrete action? F. D.: As the head of the Science and Society office, I have three main priorities. The first is to create meeting opportunities for science and society: getting people from different backgrounds to talk to each other, finding a common language, and having a fruitful dialogue. To this end, we are developing communication tools and strategies to enable people to meet and exchange ideas. Especially, we organize meeting and the national and regional scales. What is the second priority? F. D.: Funding. Today, the core activity of the department I manage is to set up seed funding. In participatory research, there is a “silent” period, during which we begin to co-construct, before carrying out the research itself. To finance this co-construction, once the projects have been selected, we allocate funding of around €15,000 for a period of 12 to 18 months. How do you go about it? F. D.: We take on projects when there’s an idea, or an observation, which may come from an association, civil society, a laboratory, or an exchange between several of these stakeholders. The next step is to transform this idea into a feasible research project, that could generate data and science. Our seed funding enable the stakeholders involved to work together to formulate the scientific questions, and develop the appropriate methodology, which will respect both the requirements of scientific methodology and the realities of the people who will be doing the research. They also plan the project’s mode of governance, the distribution of roles, reporting, and everything else required to ensure that the project runs as smoothly as possible. How many projects of this type do you finance each year? F. D.: Half a dozen. What is this co-construction stage important? F. D.: It can transform parts of the research project. When scientists design a protocol for a study without leaving their laboratory, it’s not necessarily suited to gathering the observations they’re interested in. For example, a research team working on cognitive aging, in the case of normal aging, and in the case of diseases such as Alzheimer’s disease, had the idea of exploring the memory of stage actors: these professionals tend to have a good memory, or at least good strategies for learning; and they retain their learning abilities well with age. These researchers could have established a study protocol, then recruited actors as subjects, and observed their brains as they learned texts in an MRI scanner. Had they done so, they would certainly have made observations, but far removed from what they really wanted to observe. They spent over a year working with actors to develop a protocol that took account of the real conditions under which they learn their texts, which are very different from those in an MRI scanner, which makes a lot of noise and in which you have to lie still: some actors learn only by walking around the room, for instance. Beyond adapting the methodology, are there other benefits to co-construction? F. D.: Some scientific questions from civil society are completely unexpected for scientists. And bringing new questions to light is very valuable in scientific research. For example, in Lyon, a team was working with women suffering from breast cancer. During discussions, these women said they had memory problems, cognitive problems. It has been decided to explore this, and it was shown that these cognitive issues are linked to chemotherapy. It would never have emerged among breast cancer specialists. INSERM is home to the Groupe de réflexion avec les associations de malades (GRAM), a think tank that brings together researchers, patient association representatives and members of INSERM’s central services. The GRAM is a think tank that brings together researchers, patient association representatives and members of INSERM’s central services. There is also a Collège des relecteurs: since 2007, INSERM has trained around a hundred