Assessing the perceived predictability of anxiety-related events: a report on the perceived predictability index.

Predictability, or lack thereof, is believed to play a critical role in the development and maintenance of anxiety, with unpredictability being associated with heightened levels of anxious and fearful responding. Despite the potential importance of predictability in theoretical accounts of emotional dysregulation, currently no standardized assessment instrument exists to assess predictability perceptions for anxiety-related events. The present series of four investigations report on an initial attempt to develop a self-report instrument (i.e., Perceived Predictability Index, PPI) that can measure predictability perceptions for the occurrence, duration, and termination of anxiety-related events. Initial item selection and factor structure of the instrument was based on a large sample of participants and yielded a two-factor solution: (1) prediction of anxiety-related environmental events and (2) prediction of internal events. Our subsequent studies show that the PPI possesses adequate levels of internal consistency and temporal stability over time. Additionally, the PPI demonstrated adequate divergent and convergent validity relative to other standard anxiety and fear measures. The internal dimension of the scale also demonstrated predictive validity for emotional responding during a biological challenge test. We discuss these findings in relation to the role of perceived predictability in the study of anxious and fearful responding, and offer directions for future research.