UC San Diego

Research examining the benefits of mindfulness have expanded exponentially over the past few decades, yet the field faces criticism for lacking methodological rigor, particularly in terms of how mindfulness is measured. Most of the effort towards developing psychometrically sound self-report measures has been made regarding trait mindfulness. However, there is good reason to develop valid and reliable state measures since mindfulness is often referred to as a momentary state that is experienced during formal practices like meditation, as well as throughout instances of daily life, to varying degrees. Although a handful of existing state mindfulness measures have merit, I argue the need for a new measure that is brief, multidimensional, accessible to the general population, and versatile to various experimental designs. With these motivations in mind, the goal of this dissertation is to improve the methodological rigor by which researchers can analyze the benefits of mindfulness. In Chapter 1, I create and validate a new measure of state mindfulness, the State Four Facet Mindfulness Questionnaire (“state-FFMQ”), fashioned after the most widely used multidimensional measure of trait mindfulness. In an experimental setting, the state-FFMQ provides evidence of convergent, construct, predictive, and incremental validity when referencing a formal mindfulness practice. In Chapter 2, I employ the Day Reconstruction Method to show that in a naturalistic setting the state-FFMQ demonstrates these same forms of validity when referencing daily experiences of mindfulness. In both chapters, I also investigate the empirical question of which facet(s) of state mindfulness best predicts state affect and show that not all facets of mindfulness are alike. In Chapter 3, I replicate a widely-cited study that looks at the association of state mindfulness and state affect and expand on their results by quantifying the impact of a rarely evaluated yet significant confounding variable. In sum, this dissertation provides evidence that a newly created state mindfulness measure is psychometrically sound; clarifies the relative importance of each facet of state mindfulness in predicting state affect within experimental and naturalistic settings; and determines how much of the relationship between state mindfulness and state affect can be accounted for by a confounder.