In PBT, processes are defined as theoretically coherent, modifiable pathways of change that operate across biological, psychological, and sociocultural levels to influence a client’s outcomes (Hofmann & Hayes, 2019). They are different from symptoms because the focus is not only on the categorizable form or content of psychological experiences, but “on how these experiences unfold over time and influence other aspects of [the clients’] life” (Ong & Lee, 2025, p. 11); thus aligning more with the definition of the “act in context” (Hayes et al., 1988). A crucial distinction concerns what makes a process specifically therapeutic: a process earns this qualification not simply by being known to foster well-being at a group level, but by virtue of its relevance to reaching the individual’s therapeutic goals (Ong et al., 2022), thus aligning with the functional-contextualist framework (Hayes et al., 1988). The functionality of any given process is therefore evaluated relationally — with respect to what this person in a specific context needs to change to pursue their a priori set goals (Hayes, 2015).