#contributionIndependent samples support comparative robustness
The citation-growth pattern is examined separately in DOAJ- and OAD-based flipping samples with limited overlap, reducing dependence on a single OA directory.
↳ Data, DOAJ-based and OAD-based approaches, pp. 5–6; Table 3, pp. 15–16
#methodological rigourTwo control strategies address journal differences
Each study journal is compared with a discipline-and-year control and a tailored control that additionally accounts for national orientation.
↳ Definition of control groups, pp. 8–9
#positioningLiterature and database limits are visible
The review includes positive, null, mixed, and critical evidence, while the limitations identify Scopus coverage, language and field biases, and residual hybrid-OA contamination.
↳ Earlier studies, pp. 3–4; Limitations, p. 20