In some contexts, the complexity of systems occupying a socio-ecological niche is a challenge for research and advisory services, as are multi-trophic rice-fish farming systems. Using a case study of a research and development project in Guinea, we reconstructed the action research process and the role played by each actor, and conducted semi-structured interviews with the participants farmers, technicians, researchers and project managers. We describe the implemented participatory and collaborative experimentation, that allowed each farmer to identify, test and evaluate fish farming practices in their ponds, guided by a technician. All groups of stakeholders (farmers, technicians, and researchers/project executives) perceived improvements in their ability to manage or advise about multi-trophic rice-fish farming systems, and collective exchanges played a key role in the process.To support farmers in the adaptation and mangement of complex systems, the goal is not to anticipate all the situations farmers might encounter, but to equip them with knowledge and experimentation skill in order to deal with a wide range of situations. Co-learning allowed the project staff to link their knowledge about biological phenomenon with the repertoire of technical options available to farmers considering their constraints and priorities. However a change in posture from all stakeholders is a prerequisite to enable co-learning.