5 - (SYM 129) We Can Define It, but How Do We Actually Measure It? A Content Analysis of Psychological Flexibility Scales

Acceptance and commitment therapy (ACT) places a significant emphasis on understanding the constructs of psychological flexibility and inflexibility. Thus, they are fundamental in evaluating ACT theory. Measuring a construct as complex as psychological flexibility poses many challenges. Along with other psychometric concerns, a critical aspect of measurement is potential content overlap between scales designed to measure the same or similar constructs. Data will be presented from a study that explored content overlap among nine commonly used psychological flexibility and inflexibility scales. Forty item categories were identified following the classification procedure. None of these categories were covered by all nine scales. Across the scales, the Jaccard Index was 0.13, indicating very weak category overlap. This inconsistency poses a challenge for research focused on psychological flexibility and inflexibility as it hampers the ability to synthesize data across different studies effectively. Other features of the item content were also considered and will be discussed. Items were relatively split between measuring psychological flexibility (42.9%) and inflexibility (57.1%). Notably, 78.5% assessed some type of internal experience or relationship with an internal experience. These included, feelings and emotion (41.1%), thoughts (28.2%), worries (3.1%), memories (2.5%), physical discomfort/sensations (2.5%), and nondescriptive “experiences” (1.2%). The findings underscore the need to clarify the definitions of psychological flexibility and inflexibility with respect to items on a self-report scales and practice  greater transparency when reporting on study measures (e.g., construct of interest, scale selection, psychometric data).