The social domain has seen a growing debate on the effectiveness of public
measures. The realisation is taking shape that the legitimacy of social
policies such as the socialisation of vulnerable groups, anti-radicalisation
programs or regeneration projects in deprived neighbourhoods has to go
beyond the intuition that they `should work. But unlike methods in spheres
such as medicine and healthcare, social programs typically have no sharp
demarcation in time, intensity or target group and are implemented in a
rich context of unforeseen and unknown variables. This makes it difficult
(if not impossible) to assess their impact with research methods that
centralise a monocausal effect.