Table 7 Characteristics and example of Subtype C3

Characteristics of Subtype C3: Longitudinal process approach

- The aim is to investigate change processes or incitements to change

- The results present stages or phases and often preconditions, incitements and consequences, thus explaining how change occurs

- The results focus on the process of change and stages of change. Thus, time is of lesser interest. The change process is not necessarily chronological; multiple moves forward and backward between the stages of change are common

Example: Elliott and colleagues [32] investigated adolescent mothers’ housing instability across three years. They then developed a theory to describe the process of how mothers strove for independent housing, including descriptions of types of moves and factors affecting housing instability. Within this theory, horizontal moves were described as mothers moving to a similar housing situation (e.g., moving from living with one family member to another) and vertical moves as mothers moving from a dependent housing situation to an independent housing situation (e.g., an own contract). During the data collection, some mothers underwent several horizontal moves, and others experienced just one vertical move. The theory was developed by taking all the participants into account. This article provided interpretive results and suggested possible explanations and mechanisms for change