Highly Cited Researchers: How Clarivate Selects the List

Clarivate’s Highly Cited Researchers (HCR) list names researchers whose work ranked among the most-cited in their field over the past decade — but the list itself is not just a citation-count leaderboard. It is a curated award, built from a citation threshold and then narrowed by additional review. This guide explains the actual mechanics: the Essential Science Indicators (ESI) basis the list starts from, the field categories including the “Cross-Field” award, what is filtered out before a name makes the final list, and where the process has visible limits.

What “Highly Cited Researcher” actually means

Clarivate’s own description of the award is direct: researchers are selected for having “authored multiple Highly Cited Papers which rank in the top 1% by citations for their field(s) and publication year.” A Highly Cited Paper, in turn, is an ESI concept — see CASRAI’s guide to Essential Science Indicators for how that top-1% threshold is actually computed field by field, on a rolling ten-year citation window, recalculated at every bimonthly ESI update.

That distinction matters for anyone citing the award correctly: ESI’s Highly Cited Papers and Clarivate’s Highly Cited Researchers list are related but separate products. Having one or more Highly Cited Papers in ESI does not, by itself, make a researcher an HCR — the list applies its own additional criteria on top of the ESI paper count, described below. Conflating the two in a CV, a tenure dossier, or an institutional ranking submission overstates what either credential actually certifies.

The selection process: citation count first, then review

Clarivate is explicit that the citation threshold is a starting filter, not the entire process: “citation activity is not the sole selection indicator. This list, based on citation data, is then refined using other quantitative metrics, as well as qualitative analysis and expert judgment.” In practice this means the HCR list is built in two stages:

1. Quantitative screening. Web of Science Core Collection data is used to identify authors of multiple ESI Highly Cited Papers — papers in the top 1% by citations for their field and publication year, over the relevant multi-year window.
2. Refinement. The resulting candidate pool is narrowed using additional quantitative signals plus qualitative and expert review, rather than being published as a raw citation-count ranking.

Clarivate does not publish the full technical specification of that second stage as an open methodology document with every threshold and rule enumerated — the published description states the categories of input (quantitative metrics, qualitative analysis, expert judgment) without a fully itemized rulebook. Anyone citing the list’s rigor should represent it at that level of precision rather than implying a fully mechanical, auditable formula exists.

The field categories, including “Cross-Field”

HCR researchers are recognized within Clarivate’s field-based structure — the same broad discipline categories used across ESI — plus one deliberately different category:

• Field-specific categories (Biology & Biochemistry, Chemistry, Clinical Medicine, and the rest of ESI’s broad-field list) recognize researchers whose Highly Cited Papers cluster within a single ESI field.
• Cross-Field recognizes researchers whose citation impact is substantial but distributed across multiple fields rather than concentrated in one — work that would understate a researcher’s actual influence if forced into a single-field count, or that simply reflects a genuinely interdisciplinary research program.

This mirrors a structural point covered on CASRAI’s ESI guide: ESI field assignment is journal-based, and a paper inherits exactly one field from the journal it appeared in. A researcher who publishes across several ESI fields can accumulate Highly Cited Papers in more than one field without any single field’s count clearing the bar on its own — the Cross-Field category exists specifically to still recognize that researcher rather than let interdisciplinary impact fall through the gaps of a single-field count.

What gets excluded before a name qualifies

Because the list is built from citation counts, it inherits the same manipulation risks any citation-based metric does — and Clarivate applies exclusion criteria aimed at those risks before finalizing the list, on top of the qualitative review described above. Documented exclusions, drawn from Clarivate’s own list criteria as summarized in secondary reporting, include:

• Retracted publications are not counted toward a researcher’s Highly Cited Paper total.
• Papers with unusually large author lists (reporting commonly cites a threshold around 30+ authors) and papers carrying only explicit group/consortium authorship are excluded from qualifying — a hyper-authorship control aimed at papers where citation credit is diffused across dozens or hundreds of contributors rather than reflecting one researcher’s identifiable contribution.

These controls exist because the failure mode is real and has happened publicly: in the 2023 edition of the list, Clarivate removed mathematics as a qualifying field entirely after identifying citation-cartel activity — coordinated reciprocal citation designed to artificially inflate citation counts — distorting that field’s results. The field was later reinstated once the underlying data issue was addressed. That episode is the clearest public evidence that Clarivate’s screening is a real, applied filter, not a formality: an entire field’s worth of otherwise-qualifying citation counts was set aside rather than published once anomalous citation behavior was detected.

What is not independently confirmed (flagged honestly rather than asserted): Clarivate’s public HCR pages do not spell out a specific self-citation exclusion rule for the HCR list the way some other Clarivate products document theirs — for comparison, Journal Citation Reports does not strip self-citations from the headline Journal Impact Factor, but does disclose each journal’s self-citation rate separately and can suspend a journal from JCR for extreme self-citation or reciprocal citation stacking. Whether HCR applies an analogous author-level self-citation adjustment, and the exact year any specific hyper-authorship threshold was first introduced, are not stated in Clarivate’s own public HCR pages as fetched for this guide. Treat the exclusion criteria above as confirmed; treat a specific self-citation formula or introduction date as unconfirmed until verified directly against Clarivate’s current methodology page.

Scale of the list

The list is a global, cross-institutional award, not a small honor roll: the 2025 edition recognized 7,131 Highly Cited Researcher awards. Because one researcher can hold both a field-specific award and a Cross-Field award in some cases, the award count and the unique-researcher count are not always identical — check Clarivate’s own list release notes for the current year’s exact figures rather than reusing a prior year’s count, since both the total and the field distribution change annually as citation data and field boundaries shift.

Why this matters for research administrators

The list shows up in contexts with real institutional stakes, and getting the citation right matters in each:

• University rankings. The Academic Ranking of World Universities (ARWU/Shanghai Ranking) weights the number of an institution’s Clarivate Highly Cited Researchers at 20% of its total score (the “HiCi” indicator) — one of the largest single weightings in that ranking’s formula, second only to the Nobel/Fields-medal “Award” indicator.
• Tenure, promotion, and hiring dossiers. HCR status is sometimes cited as evidence of sustained international impact. Because the underlying threshold, field structure, and exclusion criteria change from year to year, a dossier should cite the specific year of the award, not just “HCR status” as a timeless credential.
• Institutional benchmarking and research-portfolio reporting. Counting HCRs by field is a common shorthand for departmental strength — but given the Cross-Field category exists precisely because single-field counts can understate interdisciplinary impact, a portfolio report that only tallies field-specific HCRs without checking Cross-Field awards can undercount genuinely high-impact interdisciplinary researchers.

For the underlying citation-threshold mechanics that HCR draws on, see CASRAI’s guide to Essential Science Indicators. For a different institution-level, percentile-based impact indicator with its own methodology (and its own transparency commitments), see the guide to the CWTS Leiden Ranking and the Leiden Manifesto — useful context for how one product (HCR) compares to a competing approach that publishes its full indicator methodology openly. For the author-level indicator this list is sometimes confused with, see the dictionary entry on the h-index, and CASRAI’s guide on how many citations is “good” for citation-count context more broadly.

Frequently asked questions

Is being a Highly Cited Researcher the same as having Highly Cited Papers in ESI?

No. ESI Highly Cited Papers are the underlying citation-threshold data (top 1% by citations, field and year). The Highly Cited Researchers list is a separate, additionally-reviewed Clarivate publication built from that data, with its own qualitative refinement stage. A researcher can have Highly Cited Papers in ESI without being named an HCR.

What is the “Cross-Field” category?

It is a category alongside Clarivate’s field-specific award categories, recognizing researchers whose citation impact is distributed across multiple fields rather than concentrated in one — work that could otherwise fall short of any single field’s threshold despite substantial total impact.

Does a high self-citation rate disqualify a researcher from the HCR list?

Clarivate’s public HCR pages do not publish a specific, itemized self-citation formula for this list. What is confirmed is that citation counts are refined by additional quantitative and qualitative review before the final list is published, and that entire fields have been excluded in a past edition (mathematics, 2023) after anomalous, cartel-like citation activity was identified. Treat any more specific self-citation rule as unconfirmed unless checked directly against Clarivate’s current methodology documentation.

Why does the HiCi indicator matter for university rankings?

ARWU (Shanghai Ranking) weights the count of an institution’s Clarivate Highly Cited Researchers at 20% of an institution’s total score — one of six indicators in that ranking’s formula, and one of the larger single weightings in it.

This guide covers Clarivate’s Highly Cited Researchers list as currently documented on Clarivate’s own public pages. Clarivate periodically revises its methodology and its published year-over-year totals; verify the current criteria and figures directly against Clarivate’s Highly Cited Researchers site before relying on a specific number or rule in a submission with real institutional consequences.