arxiv.org is now the most-cited graded source in AI Security & Privacy / Top lists, cited in 26.91% of that segment's observed runs, replacing ovaledge.com. At 223 observed runs, it is the largest segment whose leader was replaced outright; 15 segment leaders changed against the release a week earlier, all listed below.
In the October 19, 2026 release of the Machine Relations Index (mri_score_v2.1+2026-10-19+da0ee4378219), reddit.com was cited in 8.92% of observed AI answer runs, 2,478 of 27,776: the highest citation rate of the 31,998 source domains the Index has seen cited, at confidence tier A. In the release a week earlier (mri_score_v2.1+2026-10-12+7925b6c15feb), its rate was 10.02%, 2,399 of 23,940 runs. Across the 156-day window it was cited by Gemini, Google AI Mode, Google AI Overviews and Perplexity, and not by ChatGPT or Claude.
This is the weekly Machine Relations Index Report, built by code from the Index's daily public release and compared with the release of October 12, 2026. Every figure links to the Index page that publishes it. The previous edition is Machine Relations Index Report, October 12, 2026: reddit.com is cited in 10.02% of 23,940 observed AI answer runs.
The release at a glance #
| Measure | Release 2026-10-12 | Release 2026-10-19 | Change |
|---|---|---|---|
| Observation window | 149 days | 156 days | +7 days |
| Observed answer runs | 23,940 | 27,776 | +3,836 |
| Citation events | 183,746 | 202,867 | +19,121 |
| Cited source domains | 29,665 | 31,998 | +2,333 |
| Eligible questions in the basket | 1,108 | 1,227 | +119 |
| Published segments | 115 of 151 | 120 of 151 | +5 |
| Segments still collecting | 36 | 31 | -5 |
| Graded domains, tiers A / B / C | 19 / 101 / 648 | 22 / 117 / 740 | +111 |
A segment is one subject category paired with one question shape. It publishes once it has 10 observed runs across 7 distinct run dates. A citation rate is the share of observed answer runs in which at least one engine cited the domain.
The ten most-cited sources #
| Rank | Source | Source role | Citation rate | Runs cited | Tier | Engines citing | Rank a week earlier |
|---|---|---|---|---|---|---|---|
| 1 | reddit.com | Community and social platform | 8.92% | 2,478 of 27,776 | A | 4 of 6 | 1 |
| 2 | youtube.com | Search or media platform | 6.87% | 1,907 of 27,776 | A | 6 of 6 | 2 |
| 3 | linkedin.com | Community and social platform | 5.43% | 1,509 of 27,776 | A | 6 of 6 | 3 |
| 4 | forbes.com | Editorial publication | 3.81% | 1,058 of 27,776 | A | 6 of 6 | 4 |
| 5 | medium.com | Community and social platform | 3.54% | 984 of 27,776 | A | 6 of 6 | 5 |
| 6 | techradar.com | Editorial publication | 2.84% | 788 of 27,776 | A | 6 of 6 | 7 |
| 7 | arxiv.org | Academic and government source | 2.71% | 752 of 27,776 | A | 6 of 6 | 6 |
| 8 | g2.com | Market and company database | 2.45% | 681 of 27,776 | A | 6 of 6 | 8 |
| 9 | nih.gov | Academic and government source | 2.28% | 634 of 27,776 | A | 6 of 6 | 9 |
| 10 | yahoo.com | Editorial publication | 1.95% | 543 of 27,776 | A | 5 of 6 | 11 |
Rates are measured over all 27,776 observed runs, so they read lower than any single segment's rate. "Engines citing" counts the engines observed citing the domain at least once in the window. The public release does not publish a per-engine citation rate, so this report does not rank sources engine by engine.
The ten most-cited editorial publications #
| Rank among 1,036 classified editorial publications | Publication | Citation rate | Runs cited | Tier | Engines citing |
|---|---|---|---|---|---|
| 1 | forbes.com | 3.81% | 1,058 of 27,776 | A | ChatGPT, Claude, Gemini, Google AI Mode, Google AI Overviews and Perplexity |
| 2 | techradar.com | 2.84% | 788 of 27,776 | A | ChatGPT, Claude, Gemini, Google AI Mode, Google AI Overviews and Perplexity |
| 3 | yahoo.com | 1.95% | 543 of 27,776 | A | ChatGPT, Claude, Google AI Mode, Google AI Overviews and Perplexity |
| 4 | healthline.com | 1.65% | 457 of 27,776 | B | ChatGPT, Claude, Gemini, Google AI Mode, Google AI Overviews and Perplexity |
| 5 | nerdwallet.com | 1.43% | 397 of 27,776 | A | ChatGPT, Claude, Google AI Mode, Google AI Overviews and Perplexity |
| 6 | techtarget.com | 1.32% | 367 of 27,776 | A | ChatGPT, Claude, Gemini, Google AI Mode, Google AI Overviews and Perplexity |
| 7 | nytimes.com | 1.03% | 287 of 27,776 | B | Google AI Mode, Google AI Overviews and Perplexity |
| 8 | cnbc.com | 0.87% | 243 of 27,776 | B | ChatGPT, Claude, Gemini, Google AI Mode, Google AI Overviews and Perplexity |
| 9 | peoplemanagingpeople.com | 0.84% | 234 of 27,776 | B | ChatGPT, Claude, Gemini, Google AI Mode, Google AI Overviews and Perplexity |
| 10 | pcmag.com | 0.83% | 230 of 27,776 | B | Gemini, Google AI Mode, Google AI Overviews and Perplexity |
Engine coverage #
| Engine | Model | Status | Days answered | Runs returned | Runs with a citation | Runs returned a week earlier |
|---|---|---|---|---|---|---|
| ChatGPT | gpt-4.1-mini-2025-04-14 | healthy | 152 | 6,272 | 5,540 | 5,386 |
| Claude | claude-haiku-4-5-20251001 | healthy | 155 | 6,376 | 5,175 | 5,484 |
| Gemini | gemini-3.8-flash | degraded | 134 | 6,374 | 2,151 | 5,483 |
| Google AI Mode | not disclosed | healthy | 114 | 1,947 | 1,517 | 1,792 |
| Google AI Overviews | not disclosed | healthy | 97 | 1,372 | 904 | 1,252 |
| Perplexity | sonar | healthy | 156 | 6,383 | 6,382 | 5,491 |
Engine counts come from the release manifest at machinerelations.ai/data/mri-release-manifest.json. An engine that answers on fewer days contributes fewer runs to every rate above.
Largest week-over-week movers among graded domains #
Of the 767 domains graded A, B or C in both releases, these rates moved most. Change is the difference between the two published cumulative rates, in percentage points. It records that a rate moved, not why: in the same week the basket went from 1,108 to 1,227 eligible questions and observed runs from 23,940 to 27,776, so a moved rate can reflect what was asked as much as how engines cite.
Rates that rose #
| Source | Tier now (a week earlier) | Rate now | Rate a week earlier | Change |
|---|---|---|---|---|
| rework.com | B (C) | 0.37% | 0.29% | +0.08 pts |
| cdp.com | B (B) | 0.57% | 0.50% | +0.07 pts |
| tomsguide.com | B (B) | 0.80% | 0.74% | +0.06 pts |
| monday.com | B (B) | 0.70% | 0.65% | +0.05 pts |
| nhimg.org | B (B) | 0.57% | 0.52% | +0.05 pts |
Rates that fell #
| Source | Tier now (a week earlier) | Rate now | Rate a week earlier | Change |
|---|---|---|---|---|
| reddit.com | A (A) | 8.92% | 10.02% | -1.10 pts |
| youtube.com | A (A) | 6.87% | 7.32% | -0.45 pts |
| linkedin.com | A (A) | 5.43% | 5.87% | -0.44 pts |
| medium.com | A (A) | 3.54% | 3.94% | -0.40 pts |
| nih.gov | A (A) | 2.28% | 2.56% | -0.28 pts |
Segment leaders that changed #
| Category | Question shape | Leader a week earlier | Leader now | Rate now |
|---|---|---|---|---|
| AI Infrastructure | Is it worth it | reddit.com, 19.49% | medium.com and reddit.com (tied) | 16.89% |
| AI Security & Privacy | Is it worth it | witness.ai, 16.89% | ovaledge.com and witness.ai (tied) | 16.06% |
| AI Security & Privacy | Problem-first research | arxiv.org and techradar.com (tied), 14.95% | techradar.com | 13.84% |
| AI Security & Privacy | Top lists | ovaledge.com, 27.32% | arxiv.org | 26.91% |
| AI Visibility & GEO | Top lists | youtube.com, 22.50% | tryprofound.com | 21.58% |
| Consumer Products | Comparisons | youtube.com, 24.60% | petmd.com | 23.96% |
| Cybersecurity | Top lists | adaptivesecurity.com, 27.12% | hoxhunt.com | 25.12% |
| Deep Tech & Hardware | Comparisons | nvidia.com and reddit.com and youtube.com (tied), 17.31% | youtube.com | 17.20% |
| Education & Training | Top lists | reddit.com, 14.29% | d2l.com | 14.12% |
| Emergent Prosumer | How buyers choose | reddit.com, 16.08% | soundcore.com | 17.44% |
| Emergent Prosumer | Is it worth it | reddit.com, 21.77% | layer3labs.io and plaud.ai (tied) | 20.34% |
| Enterprise Software | Top lists | procuredesk.com, 17.69% | procurify.com | 16.38% |
| Fintech | Comparisons | wise.com, 19.48% | fraud.net and wise.com (tied) | 17.93% |
| Healthcare Services | How buyers choose | omnimd.com, 11.18% | adsc.com | 9.89% |
| Logistics & Freight | Problem-first research | linkedin.com and wearewarp.com (tied), 8.57% | wearewarp.com | 9.00% |
A leader is the graded domain outside the publisher's related parties with the highest citation rate in the segment, on the segment's own denominator; domains tied on rate are listed together.
Segments that crossed the evidence floor #
| Category | Question shape | Runs observed | Run dates | Leader | Rate |
|---|---|---|---|---|---|
| Local Services | Top lists | 110 | 7 | angi.com | 25.45% |
| Logistics & Freight | Best tools | 107 | 7 | softwareadvice.com | 16.82% |
| Logistics & Freight | How buyers choose | 102 | 7 | freightwaves.com | 18.63% |
| Logistics & Freight | Is it worth it | 107 | 7 | shipperguide.com | 21.50% |
| Logistics & Freight | Top lists | 107 | 7 | gofreight.com | 12.15% |
Segment leaders by category #
The leader of every published segment, with its citation rate on that segment's runs. "Collecting" segments have not yet cleared the evidence floor of 10 runs across 7 run dates and carry no leader.
Do the cited sources support the answer? #
Answer-Source Fidelity is a separate measurement of claim support, not citation frequency. This edition preserves the published Fidelity snapshot generated 2026-10-18T11:37:55.303Z; it is not a week-only rate and may cover a different observation period from the Index.
Legacy baseline — frozen corpus, grade-time fetch basis #
Semantic cohort: c74383df31771cfe. Cohorts with different measurement semantics are not pooled.
- ChatGPT (reported): Of the 1255 resolvable citations for this engine, 54.8% were Supported; resolvable coverage was 77% (1255/1630).
- Claude (collecting): Engine still COLLECTING: only 88 of 1361 citations were resolvable (coverage 6.5%) — below the evidence floor, so no fidelity rate is reported.
- Gemini (collecting): Engine still COLLECTING: only 392 of 4349 citations were resolvable (coverage 9%) — below the evidence floor, so no fidelity rate is reported.
- Perplexity (reported): Of the 1298 resolvable citations for this engine, 50.1% were Supported; resolvable coverage was 47.6% (1298/2726).
Collection-time series — snapshot basis, bounded snapshot retry + deferral (F4-3) #
Semantic cohort: 06ddb22c15fa05d0. Cohorts with different measurement semantics are not pooled.
- ChatGPT (reported): Of the 11562 resolvable citations for this engine, 53.4% were Supported; resolvable coverage was 76.9% (11562/15037).
- Claude (collecting): Engine still COLLECTING: only 0 of 0 citations were resolvable (coverage 0%) — below the evidence floor, so no fidelity rate is reported.
- Gemini (collecting): Engine still COLLECTING: only 0 of 0 citations were resolvable (coverage 0%) — below the evidence floor, so no fidelity rate is reported.
- Perplexity (collecting): Engine still COLLECTING: only 0 of 0 citations were resolvable (coverage 0%) — below the evidence floor, so no fidelity rate is reported.
Published dataset SHA-256: 3dee00d65907f16c1f7610da848fa2d4a42f979fdee5f723dbc5960fcb9bc049. Current measurement and method · Current dataset. The linked dataset advances; the snapshot above stays fixed with this edition.
How this report is built #
- Source: Machine Relations Index release
mri_score_v2.1+2026-10-19+da0ee4378219(methodology mri_score_v2.1, window 2026-05-10 to 2026-10-19), compared withmri_score_v2.1+2026-10-12+7925b6c15feb. The current release is public at machinerelations.ai/data/machine-relations-index.json; figures for the earlier release are read from the same file as committed on 2026-10-12. - Rates are cumulative over the observation window, not rates for the week alone. Week-over-week change compares two published rates and is never read as a cause.
- Only segments the release publishes, at 10 or more observed runs across 7 or more run dates, are reported. Only domains with a confidence tier (A, B or C) are ranked or listed as movers; tiers are the Index's own.
- Domains operated by the publisher of this site or its related parties (authoritytech.io, machinerelations.ai, jaxonparrott.com, christianlehman.com, presspool.ai, paralabs.ai, paralax.ai) are left out of every ranking in this report. Their Index profiles remain public.
- The method is set out at machinerelations.ai/index, and known data issues and corrections are logged in the Index methodology and update log. Corrections to an edition are made there and in the edition.
FAQ #
What is the Machine Relations Index Report? A weekly reading of the daily public release of the Machine Relations Index: the most-cited sources, the largest movers among graded domains and the leader of every published segment, each figure tied to a release id and linked to the Index page that publishes it.
Does a first place mean a source is better? No. It means answer engines cited it most often for that question shape in that category during the window. The Index measures citation, not accuracy; whether a cited source supports the answer is a separate measurement.
Why can a rate fall while a source gains citations? A rate is citations over observed runs. reddit.com was cited in 2,478 runs this week against 2,399 a week earlier, while observed runs grew to 27,776; the rate moves with both.