The opportunities of engaging the public in the scientific process of problem formulation,
data collection, analysis,
and evaluation have to be seen in this wider context of global
sustainability research. It is important to note however, that in the same way as there are
different levels of participation, from manipulation and therapy (which are non-participation)
to informing, and placating (tokenistic), all the way to partnership and citizen control,
(Arnstein 1969) there are multiple degrees of public engagement in citizen science. Haklay
(2011) distinguishes between four levels of Citizen science, from citizens as sensors at the
lowest level, to Participatory Science and Extreme Collaborative Science (See figure 1).