The European Citizen Science Association describes citizen science as follows: "Citizen science is an ‘umbrella’ term that describes a variety of ways in which the public participate in science. The main characteristics are that: (1) citizens are actively involved in research, in partnership or collaboration with scientists or professionals; and (2) there is a genuine outcome, such as new scientific knowledge, conservation action or policy change. (...) Citizen science takes place in diverse fields, including ecology, astronomy, medicine, computer science, history – and many more. And citizen science can happen at a range of different scales – from local projects to continental and global scales, and from short projects to those that occur over decades!"