“…Given the disappointing findings emerging from training studies and the recognition that context was important (McHugh & Barlow, ), implementation research entered a third wave, focused primarily on identifying determinants at multiple levels (e.g., clinician, organization, system) that might be related to implementation success or failure spurred on by the publication of several heuristic implementation frameworks (Aarons, Hurlburt, & Horwitz, ; Damschroder et al., ; Greenhalgh, Robert, Macfarlane, Bate, & Kyriakidou, ). Third wave studies often used mixed‐methods to describe the determinants or test the relationships between these determinants and a variety of implementation outcomes such as EBP adoption, fidelity, and sustainment (Beidas et al., , ; Locke et al., ; Palinkas et al., ; Stein, Celedonia, Kogan, Swartz, & Frank, ). We refer to this approach as the ‘ disaggregation paradigm’ because it involves dismantling established social science theories such as the Theory of Planned Behavior (Ajzen, ), Social Cognitive Theory (Bandura, ), Learning Theory (Blackman, ), and Organizational Climate Theory (Ehrhart, Schneider, & Macey, ) into their constituent variables (e.g., attitudes, organizational culture), measuring a large number of these variables in a single study, and examining which are most strongly associated with implementation in a single multivariate model that includes all measured variables.…”