Abstract: In participatory urban planning, understanding local stakeholders’ viewpoints is central, and, thus, gathering local knowledge has become a frequent task in planning practice. However, the built cultural heritage is usually evaluated by experts neglecting the values and opinions of citizens. In this study, a crowdsourcing model for assessing local residents’ viewpoints and values related to the built cultural heritage of Nikkilä was developed. The aim was to find out if crowdsourcing with public participation GIS and social media is a functional method for revealing local people’s values, place-based memories and experiences. In the case study, non-professional knowledge was compared with expert knowledge and valuable knowledge about the intangible aspects of the built cultural heritage was reached through place-based memories. Apart from that, social media provided visual representations of place-based experiences and a tool for building a collective memory. Based on the results, it is evident that a multi-method crowdsourcing model can be a functional model for crowdsourcing local knowledge. However, there are several challenges in analysing data and using the knowledge in urban planning.
Keywords: crowdsourcing; cultural heritage; place-based memories; PPGIS; social media; urban planning