Resumen
Decisions are a key element of spatial planning processes and in the face of increasing public participation in local governance, they become even more complex. The diversity of stakeholders in planning processes causes a significant increase in the number and scope of articulated expectations, needs, and knowledge that could be integrated into the process. Along with the participatory approaches in spatial planning, a departure from the expert-oriented decision-making model towards its collaborative form is expected. As everyday users of space, residents have knowledge about the functioning of its elements resulting from their experience, the so-called experiential knowledge. The study aimed to investigate the role of residents? input in diagnosing space in spatial planning processes using public participation geographic information systems (PPGIS). The article presents the study?s results conducted in Poznan, Poland, among residents and urban planners using geo-questionnaires and in-depth interviews. The article presents the characteristics of the residents? contribution to the spatial diagnosis and the possibilities and limitations of the involvement of residents? knowledge collected using a geoweb tool in the professional work of urban planners.