The Application of Intensive Longitudinal Methods to Investigate Change: Stimulating the Field of Applied Family Research

The use of intensive longitudinal methods (ILM)—rapid in situ assessment at micro timescales—can be overlaid on RCTs and other study designs in applied family research. Particularly, when done as part of a multiple timescale design—in bursts over macro timescales—ILM can advance the study of the mechanisms and effects of family interventions and processes of family change. ILM confers measurement benefits in accurately assessing momentary and variable experiences and captures fine-grained dynamic pictures of time-ordered processes. Thus, ILM allows opportunities to investigate new research questions about intervention effects on within-subject (i.e., within-person, within-family) variability (i.e., dynamic constructs) and about the time-ordered change process that interventions induce in families and family members beginning with the first intervention session. This paper discusses the need and rationale for applying ILM to family intervention evaluation, new research questions that can be addressed with ILM, example research using ILM in the related fields of basic family research and the evaluation of individual-based interventions. Finally, the paper touches on practical challenges and considerations associated with ILM and points readers to resources for the application of ILM.