Resumen
Citizen Science crystallised as an umbrella term for public participation in scientific research, Volunteered Geographic Information (VGI), Citizens? Observatories, and many more. Technological advancements clearly power the wealth and spread of related initiatives, and organisational structures could be established over the past few years. On the one hand, most of the data collected or analysed by these initiatives, such as biodiversity records, air quality information or waste maps, have a spatio-temporal component. On the other hand, many Citizen Science initiatives reply on spatial data in order to plan or carry out their activities. Thus it is legitimate to ask if and how these recent developments might influence Spatial Data infrastructure (SDI) research. In 2018, the International Journal of Spatial Data Infrastructure Research (IJSDIR) for the first time showcases possible future scenarios in a dedicated Special Section on Citizen Science. The editorial at hand sets the scene for this Special Section.