Evidence
How established and verifiable the result is. Rewards work that has cleared peer review, been independently built upon, and can be read and checked in the open. Retraction collapses it.
| Sub-metric | Source signal | How it maps to 0 to 100 | Weight |
|---|---|---|---|
| Peer review & venueWhether the work has cleared peer review, and how selective its venue is. Peer review is necessary but not sufficient: before citations accrue, a fresh result in the most selective venues (Nature, Science, Cell, NEJM, the Lancet, PNAS, Physical Review Letters/X) is a stronger evidence signal than one in a legitimate but very high-volume mega-journal, which in turn outranks a preprint that has not been reviewed at all. | OpenAlextype / primary_location / source | Peer-reviewed article graded by venue prestige: flagship 100, elite-family 90, high-volume mega-journal 78. Review 90, book 70, dataset 60, preprint 45, other 55. | 0.30 |
| CorroborationIndependent corroboration that the result is real and being taken up, read as the BREADTH of agreement rather than the size of the citation pile. Counts how many of the five independent citation indices (OpenAlex, Crossref, Semantic Scholar, OpenCitations, Europe PMC) report the work at all, plus orthogonal, non-citation lines of corroboration: entry into the encyclopedia, registered clinical trials, released datasets or software, public funding on record, and technical-community discussion. Citation MAGNITUDE is deliberately judged under Impact, not here, so Evidence and Impact measure genuinely different things instead of both rewarding the same citation pile twice. | OpenAlex, Crossref, Semantic Scholar, OpenCitations, Europe PMC, DataCite, NIH RePORTER, Wikipedia, Hacker Newscount of agreeing indices + orthogonal reach | Starts at 28 and rises with each of the five independent citation indices that agree the work is cited (+9 each) and each orthogonal non-citation corroboration line (+6 each: Wikipedia, clinical trials, open datasets or software, public funding, community discussion). Capped at 100. | 0.30 |
| VerifiabilityHow openly the result can be read, reused, and reproduced. Rewards open access, a permissive reuse license (CC-BY/CC0), a green repository copy anyone can archive, openly minable full text, and released datasets or software a reader can actually run. Cross-checked across OpenAlex, Unpaywall, Europe PMC, and DataCite. | OpenAlex, Unpaywall, Europe PMC, DataCiteis_oa / license / has_repository_copy / open datasets | Closed 45; open access 80+; a permissive CC license 100; a repository copy, open full text, or a released dataset/software artifact each raise the floor. | 0.20 |
| IntegrityRetraction and post-publication correction status. A retracted result is not evidence of anything and collapses the whole Frontier Score; a correction or expression of concern is a softer flag. Read across OpenAlex and Crossref (both update-to and updated-by notices). | OpenAlex, Crossrefis_retracted / update-to / updated-by | Clean 100; a correction or expression of concern 75; retracted 0. Flagged if OpenAlex OR Crossref records the notice. | 0.20 |
Impact
How much the result matters, judged field-relative and by current momentum. Anchored on field-weighted citation impact (so a small field and a large field are judged fairly) and on how fast the work is being taken up right now. Raw lifetime citation volume is deliberately not rewarded: on the frontier, a large pile signals a result is already established.
| Sub-metric | Source signal | How it maps to 0 to 100 | Weight |
|---|---|---|---|
| Field-normalized impactImpact relative to the world average for the same field, year, and type, so a small field and a large field are judged fairly. Triangulates three independent field-normalized measures: OpenAlex's Field-Weighted Citation Impact, its citation percentile within the exact field-and-year cohort, and the NIH iCite Relative Citation Ratio. 1.0x is average; the percentile is the share of same-field, same-year work it out-cites. | OpenAlex, NIH iCitefwci / citation_normalized_percentile / relative_citation_ratio | Each ratio (1.0 = field average) maps 1.0 to 50, 3.0 to 75, 9.0 to 90; the field+year percentile maps directly (top 1% -> ~99). The available measures are averaged. Falls back to a saturating citation count when none is available yet. | 0.45 |
| Influential citationsCitations that genuinely build on the work rather than mention it in passing (Semantic Scholar's influential-citation measure). A sharper signal of real impact than a raw count. | Semantic ScholarinfluentialCitationCount | Saturating: 15 influential citations maps to 50. Falls back to a fraction of consensus citations when unavailable. | 0.20 |
| Citation velocityCitations received in the trailing twelve months, judged as a rate rather than a lifetime total. Momentum is what a frontier index cares about: a result being taken up fast right now is landing, whether its lifetime pile is large or still small. Where an expected field citation rate is known, the momentum is also read relative to it, so a fast-moving result in a quiet field is not overlooked. | OpenAlex, NIH iCitecounts_by_year / field_citation_rate | Saturating: 30 citations in the last twelve months maps to 50. When NIH iCite provides the field's expected rate, this is blended evenly with the ratio of observed to expected momentum. | 0.35 |
Novelty
How genuinely new the result is, and how fast-moving. Its lead signal is intrinsic: how novel the CONTRIBUTION is, measured from the work's own content at publication, so a recent-but-commodity result no longer reads as frontier just for being recent. Rising attention and the not-yet-reviewed edge add to it.
| Sub-metric | Source signal | How it maps to 0 to 100 | Weight |
|---|---|---|---|
| Conceptual noveltyHow genuinely new the contribution is, measured at publication from the work's OWN content, not its date: how atypical its combination of research areas is versus all prior work, and whether it builds on a broad, deep base rather than only the newest papers in a fast-moving area. This is what separates a real advance from a recent-but-commodity result, and it needs no forward citations, so it is stable for brand-new work. An honestly noisy proxy (even state-of-the-art novelty measures agree only moderately with expert judgment), so it carries bounded weight and never drives the ranking alone. | OpenAlextopics + referenced_works (publication-time) | Blends two publication-time signals, each 0-100: an atypical-combination score (how unusual the pairing of the work's research topics is versus the prior literature, by pointwise mutual information) and a foundational-reach score (median age and depth of the work's references). The stronger signal weighs 0.62, the weaker 0.38. When neither is measurable (a work too thin in topics or references), the pillar renormalizes over its recency signals instead. | 0.45 |
| RecencyHow recently the work appeared. The frontier is now, so newer scores higher. | OpenAlexpublication_date | Exponential decay with a 12-month half-life from the publication date. | 0.30 |
| Attention accelerationWhether attention is rising: citations in the latest full year versus the year before. Accelerating interest signals an active, opening frontier. | OpenAlexcounts_by_year | Latest/prior-year ratio: 1x maps to 50, 2x to 75, 4x to 100. Unknown is neutral. | 0.10 |
| Edge of reviewPreprints and brand-new work sit ahead of the peer-review process. That earns novelty here (while it is discounted under Evidence), because it is where the frontier forms first. | OpenAlextype / publication_date | Preprint 95, article <6 months 80, article <18 months 65, else 45. | 0.15 |
Grounded in peer-reviewed method
The score does not invent its own idea of merit. Its field-normalized impact uses OpenAlex's Field-Weighted Citation Impact and the NIH iCite Relative Citation Ratio (Hutchins et al., PLoS Biology, 2016), both established measures that judge a work against its own field and year. Its conceptual-novelty signal operationalizes the atypical-combination method of Uzzi, Mukherjee, Stringer and Jones (Science, 2013), which measures how unusually a work pairs prior research areas. Frontier's contribution is not a new metric but a transparent, decomposable way of combining these, so every number stays traceable to a peer-reviewed basis and a primary record.
Frontier recency: why the edge is now
A result's standing decays as it ages into established practice, so the active edge stays on top. Full when new, halved about every 8 months, and never below 0.5 (a settled landmark is retained at half weight, never erased). This multiplier, applied on top of the weighted pillars, is what makes Frontier a frontier index rather than an all-time-greats list: a result that has already settled into standard practice, however heavily cited, is discounted so genuinely new work stays on top. A retraction overrides everything, collapsing the score to zero.
Tiers
The composite maps to a plain-language tier. An Early-signal result is capped at Notable and a Firming-up one at Major, whatever its score, so a tier never claims more certainty than its evidence carries.
| From | Tier | What it means |
|---|---|---|
| 60+ | Landmark | A defining advance at the current edge. |
| 50+ | Major | Strong, high-signal work with real momentum. |
| 40+ | Notable | Credible and gaining attention on the frontier. |
| 30+ | Emerging | New and promising, still proving itself. |
| 0+ | Early | Very early signal. Watch this space. |
Confidence, not just a number
A score says how a work rates; confidence says how settled that rating is. A landmark with thousands of citations across agreeing indices, cited on Wikipedia and taken into clinical trials, is “Settled”. A two-week-old preprint is an “Early signal” whose impact is still an estimate. Confidence is computed from citation maturity, time since publication, how closely the citation indices agree, and how many independent kinds of evidence corroborate the work (citation indices, field-normalized impact, encyclopedic entry, clinical trials, released code and data, public funding, community discussion). It is kept separate from the score, so a genuinely novel result is never mistaken for an uncertain one. You will see it on every breakthrough, next to its score.
What we designed around
Known ways a naive score goes wrong, and how the Frontier Score avoids each.
- 01
A single citation index can be wrong, incomplete, or gamed.
Citations are taken as the median across up to five independent indices (OpenAlex, Crossref, Semantic Scholar, OpenCitations, and Europe PMC), so no single source can distort a score. Impact also leans on Semantic Scholar's influential-citation count, the citations that genuinely build on the work rather than mention it in passing. - 02
Citations only measure what OTHER PAPERS did, not whether a result reached the world.
Frontier pulls thirteen sources, not just citation indices. A result's reach is cross-checked against entry into Wikipedia, technical-community discussion, registered clinical trials, released datasets and code, and the public grants that funded it. These do not inflate the score (which stays about frontier impact); they raise a work's CONFIDENCE, because each is an independent line of evidence that the result is real and landing. - 03
Raw citation counts favor old, re-catalogued classics, and large fields over small ones.
Impact is anchored on Field-Weighted Citation Impact (FWCI), which compares a work only to others in the same field, year, and type. Corroboration and momentum are also read against the field-and-year cohort wherever OpenAlex's percentile or iCite's field rate provides one, so a citation-dense field does not out-score a sparse one on sheer volume. Novelty separately rewards recency, so an established result cannot masquerade as a current frontier. - 04
Very recent work has almost no citations yet.
Impact leans on velocity as well as totals, FWCI is allowed to be missing rather than scored as zero, and Novelty rewards recency and rising attention. New work is not punished for being new. - 05
A retracted result can still be highly cited.
Retraction applies a hard integrity multiplier that zeroes the whole score. A retracted result is not a frontier, whatever its citation count. - 06
Preprints are unreviewed but often the leading edge.
Preprints lose points under Evidence (not yet reviewed) and gain them under Novelty (ahead of review), rather than being treated as if peer-reviewed.
What the Frontier Score cannot tell you
A single number is a lens, not a verdict. These are the limits of what it can measure, stated plainly.
- 01
Absence is not a verdict.
The index can only rank what it has ingested. A result missing from Frontier has not been judged and found wanting; it may simply not have been swept in yet. Read a low or missing entry as incomplete coverage, never as a conclusion. - 02
The newest work is an estimate.
Very recent work has little citation or field-normalized evidence yet, so its impact is a projection that will move as uptake accrues. That is exactly why every entry also carries a Confidence, shown separately from the score, and why an unsettled result is capped below the Landmark and Major tiers. - 03
Citation signals carry field and language bias.
We normalize against the field-and-year cohort wherever a field-relative measure exists (FWCI, the citation percentile, iCite's RCR), but not every signal has one. A citation-sparse field, a very new subfield, or non-English work can still be undercounted. - 04
Fields are assigned automatically.
Each breakthrough is classified into one field by an automated keyword heuristic over its OpenAlex topic. A genuinely cross-disciplinary result can land in the wrong box, or in Other. - 05
The novelty-led weighting is a choice.
Novelty carries half the composite on purpose: Frontier ranks the active edge, not the most-cited work of the decade. A different weighting would rank differently. That is an editorial judgment about what a frontier is, stated openly, not an objective fact.
How Frontier compares
Why a scored, decomposable, novelty-led frontier index is not the same thing as a citation count, an attention score, or a year-in-review.
- How is this different from Google Scholar or a raw citation count?
- Raw citation counts favor settled classics and large fields, and they say nothing about how new a result is. The Frontier Score normalizes impact against the same field and year (field-weighted citation impact and the iCite relative citation ratio), weights novelty at half the composite, and then discounts a result's standing as it settles into standard practice. So a genuinely new 2026 result can outrank a decade-old, heavily-cited paper, which is the opposite of what a citation count does.
- How is it different from Altmetric or an attention score?
- Attention scores measure buzz: news mentions, posts, and shares. That tracks what is being talked about, not what is significant or sound. Frontier scores evidence, field-relative impact, and novelty, and treats attention (Wikipedia, community discussion) only as one corroboration signal behind confidence, never as the score itself.
- How is it different from a 'state of the field' annual report?
- Those are periodic, usually single-field, and written as narrative. Frontier is live, spans every science field in one ranking, and is fully decomposable: every entry carries a score you can trace, number by number, to the primary record it came from.
- Why trust the number?
- Because it is not a black box. The entire scoring recipe is public, every figure on a breakthrough page links to the source record that holds it, and the method operationalizes peer-reviewed science-of-science metrics rather than an invented formula. You can check the inputs, the normalization, and the weights yourself.