“…At the same time, the studies validating the AAQ-II have been criticized on methodological grounds (McAndrews, Richardson, & Stopa, 2018) and the construct validity of the AAQ-II is discussed as being insufficient (Gámez, Chmielewski, Kotov, Ruggero, & Watson, 2011;Tyndall et al, 2018;Wolgast, 2014). Even though PF and ACT are transdiagnostic approaches (Benoy, Bader, & Schumann, 2015), some authors consider the AAQ-II not being specific enough for certain clinical subgroups and diagnosis-specific versions, such as the AAQ-OC for obsessions and compulsions, have been developed (Jacoby, Abramowitz, Buchholz, Reuman, & Blakey, 2018). In addition, the growing number of alternatives measures for PF, such as the Multidimensional Experiential Avoidance Questionnaire (MEAQ) (Gámez et al, 2011), the Comprehensive Assessment of Acceptance and Commitment Therapy Processes (CompACT) (Francis, Dawson, & Golijani-Moghaddam, 2016) or the Open and Engaged State Questionnaire (OESQ) underlines the importance of examining how variations of operationalizations perform in different contexts.…”