Fig. 2
From: Advancing complexity science in healthcare research: the logic of logic models
A Typology of Logic Models in Healthcare Research. Figure 2 describes logic models as having two key characteristics: firstly, whether they list model factors only or whether they also express the relationships between the factors; and, secondly, whether context is included as part of the model or whether it is omitted. While this typology implies the possibility of four types, most logic models take the form of one of three types. Logic models that model the dynamic interaction between interventions and context, the most appropriate type for complex interventions, are rare, hence the question-mark after type 4