POSI Citation Rankings
Three independently-sourced citation indicators, none of them a POSI ranking yet: OpenAlex 2-Year Citedness (a source-level preview indicator, not PCI), PCS (POSI Citation Score, a real, spec-compliant Crossref indicator — see the full PCS table), and real PCI (OpenAlex-sourced, now computed for 990 of 993 curated Global Benchmark journals — see the full PCI table). Core Collection below shows 2-Year Citedness and PCS; the Global Benchmark publisher-catalog expansion shows 2-Year Citedness only (no PCS, no total-citations figure). Only PCI determines POSI Citation Rank, Citation Percentile, and Citation Quartile — no figure shown here does yet, for either collection: no POSI-R-* release has been produced, and Global Benchmark is never assigned a Citation Rank, Percentile, or Quartile regardless of PCI's status, since it's an external validation corpus, not a POSI-admitted collection. See PJR-SPEC.md for the official methodology.
How This Preview Is Computed
Full positioning statement →Only PCI determines Citation Rank, Percentile, and Quartile
PCI[Y] = citations received during Y to citable items published in Y-1 and Y-2, divided by citable items published in Y-1 and Y-2 (PJR-SPEC.md § 5-6) — computed under a formal PJR release, which has not yet been produced (no POSI-R-* release exists — see POSI-R-1.0-SPEC.md). The 2-Year Citedness figure shown here is OpenAlex's own summary_stats.2yr_mean_citedness, taken as-is — a source-level preview indicator only, not PCI, and it does not determine any Citation Rank, Citation Percentile, or Citation Quartile.
PCI is now real for Global Benchmark — still not for Core Collection
A real, exhaustive OpenAlex fetch now computes PCI for 990 of 993 curated Global Benchmark journals (posi-data's pjr-seed-corpus-global993-2026 audit) — see the full PCI table. POSI's own Core Collection isn't covered yet: it's overwhelmingly too young (most journals first published 2025-2026) to have real 2023-2024 output to measure. Global Benchmark is never assigned a Citation Rank, Percentile, or Quartile regardless — it's an external validation corpus, not a POSI-admitted or ranked collection.
DOI/Crossref = article inventory, not citation count
Crossref (the DOI registry) is used to verify how many articles a journal has published — the "Articles" figure shown on journal records. It is not used as a second citation-counting source.
One DOI per cited work
A dataset or preprint deposited on Zenodo (or a similar archive) under its own DOI is treated as supplementary evidence, not a separate citable record — unless it is explicitly linked to the journal article's DOI as a version/supplement. This prevents the same underlying work from being counted twice under two DOIs.
No proprietary blending
POSI does not run its own citation-counting pipeline or combine raw counts into a custom formula. It displays OpenAlex's published metric with full source attribution — the same open-data-only stance applied to CVI.
PCS is real, but independently reported — it does not determine Citation Rank, Percentile, or Quartile
PCS 1.0 (POSI Citation Score, PCS-1.0-SPEC.md) is a full cursor-paginated count of Crossref's is-referenced-by-count across a trailing 4-year publication window — no article-sample cap, computed for real on 2026-08-14 (posi-data's pcs-etl-v1-global1024-2026 audit). PCS reflects citations known to Crossref through its Cited-by and metadata infrastructure; Crossref citation coverage is not exhaustive and may vary across publishers, journals, publication years, and disciplines, so PCS is a Crossref-observed indicator, not a complete census of all citations to a work. Like 2-Year Citedness, it does not determine Citation Rank, Citation Percentile, or Citation Quartile — see the dedicated POSI Citation Score page for the full table and methodology.