Monitoring is a self-regulatory process involved in making changes to behavior. Monitoring involves a person, group, or organization taking stock of the current situation, comparing this to some goal or reference value, and identifying whether or not there is a discrepancy. Noting a discrepancy can be a reason for taking additional action to ensure goals are achieved or for adjusting or disengaging from the goal. Monitoring can also identify actions required to overcome barriers to goal striving and whether these actions have the intended effects. Given that people often do not monitor their progress, termed “the ostrich problem,” interventions that prompt monitoring can be an effective way to promote changes in behavior. This chapter reviews the evidence that monitoring interventions promote changes in behavior, identifies how monitoring has been conceptualized within theoretical models and existing taxonomies of behavior change techniques, and describes some of the mechanisms by which monitoring promotes behavior change. The chapter concludes that monitoring can be an effective strategy for promoting changes in a range of behaviors and contexts but also that developing monitoring interventions can be complex. A practical guide for the development and application of monitoring strategies is also presented, based on the literature and research evidence on monitoring interventions.

The model of action phases makes a distinction between motivational (goal setting) and volitional (goal implementation) phases of goal pursuit. The model implies that changing the behavior of individuals who are in a pre-decisional action phase (i.e., have not crossed the “Rubicon” yet with respect to turning their many wishes into binding goals) needs a different approach than changing the behavior of people who are in a post-decisional phase (i.e., have crossed the Rubicon and need to implement their goals). The model is, therefore, also known as the “Rubicon” model. What exactly needs to be targeted to achieve behavior change in pre-decisional versus post-decisional individuals is addressed in the mindset theory of action phases, which explicates the Rubicon model in terms of the relevant psychological processes. It is argued that solving the tasks people face while still being pre-decisional requires different modes of thought (i.e., mindsets conceived of as a distinct assembly of activated cognitive procedures) than solving the tasks people face in post-decisional phases. These distinct features of pre-decisional (deliberative) versus post-decisional (implemental) mindsets as specified in the model need to be considered when trying to instigate behavior change. Furthermore, research on the implemental mindset has led to the discovery of a powerful self-regulation strategy promoting goal striving: the formation of implementation intentions. The chapter also outlines psychological mechanisms that underpin the facilitating effects of implementation intentions on behavior change and, when forming implementation intentions, are expected to help people to reach their goals.