Definition: A speciﬁed set of activities designed to put into practice an activity or program of known dimensions. According to this deﬁnition, implementation processes are purposeful and are described in suﬃcient detail such that independent observers can detect the presence and strength of the “speciﬁc set of activities” related to implementation.
Source: Fixsen, D. L.,et al (2005). Implementation research: A synthesis of the literature. Tampa, FL: University of South Florida, Louis de la Parte Florida Mental Health Institute, The National Implementation Research Network (FMHI Publication #231).