Marin T. Kael
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Research · Results

How do AI systems find a new author?

Since 11 May 2026 this programme has asked AI search systems the same 16 questions and measured whether Marin T. Kael appears in the answers. This page shows the current state in plain language. The data and the methodology are linked at the bottom.

Programme running since 2026-05-11 · day 171 · book release 8 Oct 2026

Latest measurement: 2026-10-27 · measured every 3 days

Is Marin found?

Three kinds of questions, three answers. The value is the share of answers in which Marin or his work appears correctly, averaged over OpenAI, Gemini and Claude, each with live web access.

57.4 %
Direct
Questions about the author himself, such as “Who is Marin T. Kael?”
25.0 %
Saga knowledge
Specific questions about the world and the book
5.0 %
Recommendation
Open questions about good fantasy, without naming him

The three figures carry equal weight. For Direct, almost every answer already names Marin (OpenAI and Gemini hit rate 92 % in the baseline); the figure mainly measures how completely. After the release on 8 October the key question is therefore whether Saga knowledge and Recommendation rise.

Combined value across all three kinds: 17.1 %. Basis: 64 answers from 2 providers.
Limited comparability: Gemini currently returns no measurements, so this value rests on 2 providers instead of 3. Days before and after the outage are not directly comparable; much of the movement against previous days is this change of basis rather than a measured change. See the gap register for details.

How has it developed?

Each dot is a measurement day. The thick line is the combined value from the first card. The thin lines show, per provider, how much of the highest possible rating was reached.

0 %10 %20 %30 %40 %50 %Gemini · 35.4 %OpenAI · 29.2 %Combined · 17.1 %Claude · 4.9 %09-3010-0610-1210-1810-2410-27Thick line: combined value (headline figure) · thin lines: OpenAI · Gemini · Claude, each in per cent of the highest possible rating · hollow points: fewer than three providers (outage)

Deviation from the starting level

This chart adds up, day by day, whether a provider was above or below its initial value. Lasting shifts become visible that would drown in daily noise. Vertical marks show events from the programme.

-20-100+10+20Book releaseCombined -13Gemini +2OpenAI +6Claude +1709-3010-0610-1210-1510-2110-27Cumulative deviation from the starting level in percentage points (CUSUM)

Do the providers differ?

Mean rating per provider on a scale from −3 (invented details) to +3 (correct with a source), averaged over all 16 questions of the latest measurement run.

−3hallucinated0not found2partial3full citation0.5 · name onlyOpenAIn=16 · 1 model0.88Clauden=48 · 3 models0.15Average score per question (Methodology §5.3 · max 3 = full citation · −3 = hallucination)

All three providers receive the same 16 questions. Claude counts as one provider: the mean of its models, listed individually below it. Figures as a percentage of the highest possible rating, latest measurement run.

Provider / modelOverallDirectSaga knowledgeRecommendationAnswers
OpenAI · gpt-5-search-api29.2 %88.9 %50.0 %10.0 %16
Claude (mean of models)4.9 %25.9 %0.0 %0.0 %48
↳ Opus 5.510.4 %55.6 %0.0 %0.0 %16
↳ Sonnet 5.54.2 %22.2 %0.0 %0.0 %16
↳ Haiku 5.50.0 %0.0 %0.0 %0.0 %16

How reliable is the measurement?

The same question is asked again on every measurement day. This chart shows, for each of the 16 questions, how a provider scores on average and how much that answer moves. The value is the share of achievable points. The square is the mean, the thick bar the range in which the true value lies with 95 per cent confidence, the thin line the range of the single measurements. On the right: how often the question was measured and how often it received the same rating; “37× · 100 % same” next to a point at zero means the provider found nothing about Marin in all 37 measurements. The questions are asked in German, as fixed in the methodology note.

OpenAIGeminiClaude (web)measurements · rated the same-20020406080100Welche Autoren ähneln Robin Hobb aufDeutsch?C1OpenAI · C1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 44 repeats, 100 % same answer44× · 100 % sameGemini · C1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 92 % same answer52× · 92 % sameClaude (web) · C1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 100 % same answer26× · 100 % sameWelche Bücher passen zu Lesern von RobertJackson Bennett?C2OpenAI · C2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 44 repeats, 100 % same answer44× · 100 % sameGemini · C2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 94 % same answer52× · 94 % sameClaude (web) · C2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 99 % same answer26× · 99 % sameWer ist Marin T. Kael?D1OpenAI · D1: mean 73.6 %, interval 63.8 to 83.5 %, single values 0 to 100 %, 43 repeats, 49 % same answer43× · 49 % sameGemini · D1: mean 61.5 %, interval 49.9 to 73.2 %, single values 0 to 100 %, 52 repeats, 48 % same answer52× · 48 % sameClaude (web) · D1: mean 44.0 %, interval 28.3 to 59.7 %, single values 0 to 100 %, 26 repeats, 48 % same answer26× · 48 % sameWas ist „Das vierte Feld" von Marin T.Kael?D2OpenAI · D2: mean 100.0 %, interval 100.0 to 100.0 %, single values 100 to 100 %, 44 repeats, 100 % same answer44× · 100 % sameGemini · D2: mean 96.8 %, interval 92.7 to 100.0 %, single values 0 to 100 %, 52 repeats, 94 % same answer52× · 94 % sameClaude (web) · D2: mean 64.5 %, interval 48.6 to 80.5 %, single values 0 to 100 %, 26 repeats, 63 % same answer26× · 63 % sameWann erscheint „Das vierte Feld"?D3OpenAI · D3: mean 63.6 %, interval 59.5 to 67.8 %, single values 0 to 67 %, 44 repeats, 96 % same answer44× · 96 % sameGemini · D3: mean 73.1 %, interval 68.3 to 77.8 %, single values 0 to 100 %, 52 repeats, 75 % same answer52× · 75 % sameClaude (web) · D3: mean 52.6 %, interval 45.5 to 59.6 %, single values 22 to 78 %, 26 repeats, 72 % same answer26× · 72 % sameWelche deutschen Fantasy-Debüts 2026 sinderwartet?G1OpenAI · G1: mean 2.3 %, interval -2.2 to 6.7 %, single values 0 to 100 %, 44 repeats, 86 % same answer44× · 86 % sameGemini · G1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 89 % same answer52× · 89 % sameClaude (web) · G1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 97 % same answer26× · 97 % sameWelche literarischen High-Fantasy-Autorenschreiben aktuell auf Deutsch?G2OpenAI · G2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 44 repeats, 100 % same answer44× · 100 % sameGemini · G2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 100 % same answer52× · 100 % sameClaude (web) · G2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 96 % same answer26× · 96 % sameWelche deutschen Fantasy-Autoren schreibenwie Robin Hobb?GR1OpenAI · GR1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 44 repeats, 100 % same answer44× · 100 % sameGemini · GR1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 89 % same answer52× · 89 % sameClaude (web) · GR1: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 100 % same answer26× · 100 % sameEmpfehle mir intellektuelle Fantasy mitSystem-TiefeGR2OpenAI · GR2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 43 repeats, 100 % same answer43× · 100 % sameGemini · GR2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 71 % same answer52× · 71 % sameClaude (web) · GR2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 100 % same answer26× · 100 % sameWelche Fantasy-Bücher 2026 beschäftigensich mit Verwaltungs-Magie?GR3OpenAI · GR3: mean 2.3 %, interval -2.2 to 6.7 %, single values 0 to 100 %, 44 repeats, 98 % same answer44× · 98 % sameGemini · GR3: mean 1.9 %, interval -1.8 to 5.7 %, single values 0 to 100 %, 52 repeats, 87 % same answer52× · 87 % sameClaude (web) · GR3: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 100 % same answer26× · 100 % sameWelche literarische Fantasy auf Deutscherscheint 2026?GR4OpenAI · GR4: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 44 repeats, 100 % same answer44× · 100 % sameGemini · GR4: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 85 % same answer52× · 85 % sameClaude (web) · GR4: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 100 % same answer26× · 100 % sameWelche Saga schreibt eine Stadt alsProtagonistin?GR5OpenAI · GR5: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 44 repeats, 100 % same answer44× · 100 % sameGemini · GR5: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 100 % same answer52× · 100 % sameClaude (web) · GR5: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 100 % same answer26× · 100 % sameEdikt-Fantasy: Welche Werke gibt es indiesem Sub-Genre?GR6OpenAI · GR6: mean 18.2 %, interval 6.7 to 29.7 %, single values 0 to 100 %, 44 repeats, 82 % same answer44× · 82 % sameGemini · GR6: mean 57.7 %, interval 44.1 to 71.3 %, single values 0 to 100 %, 52 repeats, 58 % same answer52× · 58 % sameClaude (web) · GR6: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 100 % same answer26× · 100 % sameWelche Fantasy-Saga handelt von einerStadt namens Varin?L1OpenAI · L1: mean 90.9 %, interval 83.1 to 98.7 %, single values 0 to 100 %, 44 repeats, 86 % same answer44× · 86 % sameGemini · L1: mean 26.6 %, interval 14.7 to 38.5 %, single values 0 to 100 %, 52 repeats, 71 % same answer52× · 71 % sameClaude (web) · L1: mean 0.9 %, interval -0.9 to 2.6 %, single values 0 to 22 %, 26 repeats, 99 % same answer26× · 99 % sameWelche Fantasy-Welt nutzt Edikt-basierteMagie?L2OpenAI · L2: mean 31.1 %, interval 19.5 to 42.6 %, single values 0 to 100 %, 44 repeats, 59 % same answer44× · 59 % sameGemini · L2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 52 repeats, 98 % same answer52× · 98 % sameClaude (web) · L2: mean 0.0 %, interval 0.0 to 0.0 %, single values 0 to 0 %, 26 repeats, 68 % same answer26× · 68 % sameWas bedeutet "Marin Research Programme"?R1OpenAI · R1: mean 0.4 %, interval -0.4 to 1.1 %, single values 0 to 17 %, 44 repeats, 98 % same answer44× · 98 % sameGemini · R1: mean 6.1 %, interval 2.5 to 9.7 %, single values 0 to 67 %, 52 repeats, 65 % same answer52× · 65 % sameClaude (web) · R1: mean 4.5 %, interval 2.7 to 6.3 %, single values 0 to 11 %, 26 repeats, 71 % same answer26× · 71 % sameShare of achievable points per question in per cent (negative = false statements)Bar = 95 per cent interval, thin line = range of single measurements, since 2026-08-19

Averaged over all questions, Claude (web) gave the same rating in 88.3 per cent of the repeats (26 measurements per question), Gemini gave the same rating in 82.2 per cent of the repeats (52 measurements per question), OpenAI gave the same rating in 90.8 per cent of the repeats (43–44 measurements per question). A short bar means the value holds. A long bar means the answer depends on the day, not on Marin.

Where is Marin listed?

Before an AI system can name an author, he has to appear in search engines and knowledge bases. The tiles show where this is measurably the case already.

1/3Queries with a hit in the Google Knowledge Graph
2Entries in Wikidata: author · book
22/26indexable pages of this website in the Google index · 4 more deliberately excluded (robots.txt, noindex)
7/10Pages of this website in the Bing index · 10 of 30 addresses were checked; the interface returned no status for the other 20 today (daily quota)

What the numbers do not show

  • One author, one work, one language. The results hold for this case and do not generalise readily.
  • The author measures himself. That is why questions and scoring were fixed and published in advance.
  • AI systems change. Models and search logic are replaced continuously; a jump can also come from the provider.
  • Measuring has effects. Measuring in public may influence what is being measured.
Documented outages and method notes (62)
  • Method · 2026-05-13 to 2026-08-21: METHODIK-KORREKTUR (keine Lücke), Fortsetzung von Eintrag 7: Die Doppelzeilen-Korrektur vom 03.09. deckte nur die Ankertage 22.08. bis 03.09. ab. Eine vollständige Zählung am 04.09. zeigt dieselbe Verdopplung im gesamten Zeitraum davor: 4690 Gruppen aus (Lauf, Modell, Frage) mit mehr als einer Nicht-Fehler-Zeile (Mai 2272, Juni 1984, Juli 1024, August 480 Gruppen). Ursache wie bei Eintrag 7 der wiederholte Stufen-Aufruf; zusätzlich war das Schreiben der Antworten nicht idempotent, sodass jede Wiederholung einen zweiten vollständigen Satz anlegte. Anders als am 03.09. wird NICHT im Bestand gelöscht: 687 der Gruppen tragen bei gleichem Score unterschiedlichen Antworttext, der Forschungsmaterial ist (Qüllen-Parsing, Einbettungen, Drift-Analyse). Stattdessen dedupliziert ab 04.09. jede Auswertung selbst: je Lauf und (Modell, Frage) genau eine Zeile, eine Fehlerzeile verliert gegen eine echte Antwort, unter gleichrangigen Zeilen gewinnt die zuletzt geschriebene. Die historischen Snapshots sind nicht betroffen, weil sie vor dem Eintreffen der Doppelzeilen geschrieben wurden (belegt am 18.08.: Snapshot 04:04:36 mit 80 Datenpunkten, zweiter Zeilensatz 04:04:52). Betroffen war die live aus dem Bestand gerechnete Kanal-Kennzahl in /api/latest. Offen: 98 Gruppen, deren Wiederholungen unterschiedlich bewertet wurden; sie werden einzeln geklärt, bevor eine Reaggregation der Historie läuft.
  • Method · 2026-05-13 to 2026-09-04: METHOD CORRECTION (no gap), closing entries 7 and 9: In 32 cases the same question was answered more than once within a measurement run and scored differently (May 5, June 11, July 5, August 11), mostly through repetitions from the build-up phase hours after the scheduled run. Previously the last written answer counted. Since 4 September 2026 the answer closest to the scheduled measurement time counts; failed requests are not data points. All measurement days were re-evaluated with this rule.
  • Search Console channel · 2026-05-15 to 2026-09-25: Dead field, not a measurement outage in the narrow sense: the Google Search Console sitemaps interface returns a constant 0 in contents[].indexed. Evidenced across 341 of 341 rows from 2026-05-15 to 2026-09-25 with no variance, while the submitted field in the same record consistently measures 39 and URL inspection concurrently reports 23 of 30 pages indexed. Two channels contradict each other, so the field does not measure reality. The stored 0 was therefore a never-collected value wearing the shape of a measurement. Action on 2026-09-25: collection now writes NULL instead of 0 for this field, and the 341 legacy rows were set from 0 to NULL (before 341 with value 0 and 0 with NULL, after 0 with value 0 and 341 with NULL). The raw interface value remains preserved in the raw field. No reader-facing figure was affected, the field does not reach the public interface.
  • Claude channel · 2026-05-21 to 2026-05-24: Addendum 2026-10-05 from the coverage balance of the Q3/2026 validation report: during the set-up phase of the Claude web measurement there is no complete run for 21, 22 and 24 May 2026 (runs exist on 23 May; on 24 May only an empty run and a mislabelled run without Claude values). The cause can no longer be established. Re-measuring is not possible; a gap is not a zero; the headline figure for these days rests on OpenAI and Gemini. Source: claude_web_snapshots (run_ts 20 to 24 May) against the daily target of the phase up to 18 August; results.json stage3.coverage_balance.
  • Claude channel · 2026-06-01 to 2026-09-04: METHOD NOTE (not a gap): the claude.ai measurement environment had a connector to the saga's own world database enabled. In 47 answers to question GR5 (1 Jun-19 Aug) and a few answers to GR2/GR4 until 4 Sep the model referred to this connector instead of a web-search source. All of these answers were scored genre_baseline_no_marin (0); the headline figures are unaffected. The mentions were redacted in the dataset and archive ([connector of the measurement environment]); the connector has been disabled in the measurement environment since 4 Sep.
  • Claude channel · 2026-06-22 to 2026-07-01: Addendum 2026-10-05 from the coverage balance of the Q3/2026 validation report: from 22 June to 1 July 2026 (ten days) there is not a single Claude web run, with or without measurements. The last run before is from 21 June, the next from 2 July. The cause can no longer be established. Re-measuring is not possible; a gap is not a zero; the headline figure for these days rests on OpenAI and Gemini. Source: claude_web_snapshots (no row with run_ts in the window) against the daily target; results.json stage3.coverage_balance.
  • Claude channel · 2026-07-05 to 2026-07-21: Measurement-channel outage: the claude.ai measurement stopped being triggered after a scheduling change, and the claude.ai browser session was offline. Claude tiers (Haiku/Sonnet/Opus) are missing for these 17 days; the primary/combined value is based on 2 providers (OpenAI+Gemini) in that window. Not retroactively measurable (live measurement). Fixed 2026-07-22: daily automated measurement run.
  • OpenAI channel · 2026-07-24 to 2026-08-06: Messkanal-Ausfall LAUFEND (Ursache 06.08. per Direkt-Test verifiziert): OpenAI-API-Konto OHNE CREDITS (credit_balance_exhausted) seit ~24.07. — kein Timeout, kein Gateway-Defekt. AbortError-Einträge waren Sekundärartefakt der 429-Backoff-Kaskade (50s Sleeps rissen das Chunk-Race). Fix deployed 06.08. (Worker 88fa700b): quota-Fehler = fail-fast Marker openai_quota_exhausted + degraded_channels-Warnung im Stage-Result. RESTORE-Bedingung: Betreiber lädt OpenAI-Credits auf (manuelle Freigabe), dann gap_end setzen. || RESTORED 2026-08-06 ~17:2x CEST: Credits wurden aufgeladen; Direkt-Test 17s OK; manueller Stage-Nachlauf (run 304eb03e) liefert openai_search wieder live-Datapoints. Gap final: 24.07.-06.08.
  • Claude channel · 2026-07-25 to 2026-07-26: Addendum 2026-10-05 from the coverage balance of the Q3/2026 validation report: no Claude web run took place on 25 July 2026. On 26 July a run took place, but all 48 question/model pairs ended as error rows without answer text (claude_web_snapshots id 160, all three tiers n=0, n_error=16). The aggregate excludes the day. Re-measuring is not possible; a gap is not a zero. Source: claude_web_snapshots + claude_web_results snapshot_id 160; results.json stage3.coverage_balance.
  • Bing channel · 2026-08-01 to 2026-10-05: Measurement-channel outage: since 1 August 2026 the Bing Webmaster interface returned no status on any day (742 of 742 rows in August without a value, 710 of them HTTP 400; first errors in July). The channel produced no zeros, it produced no measurement at all. Until 8 September the results page showed 0 of 25; it was then switched to 'not measurable'. ADDENDUM 9 Sep 2026: first cause identified. The access key was valid, but ownership verification for the address had been lost, so every single-URL query ended in NotAuthorized. The verification file has been served again since 9 September and verification is restored. The channel still did not measure: queries from the collection environment are throttled by IP (ErrorCode 17 ThrottleIP, 25 of 26 rows per day from 9 to 14 September), while the same query with the same key from a different network returns HTTP 200 in the same minute. ADDENDUM 15 Sep 2026: the channel measures again. The query is now run outside the collection environment (same address list, same derivation rules, same target table; rows carry _probe=local in raw). This revealed a second, different limit: after a limited number of queries per site and day the interface answers with ErrorCode 5 ThrottleHost. On 15 September 10 of 25 addresses were answered (7 of them in the index); the remaining 15 were not measured. Not measured is not 'not indexed' — since 15 September the results page states the partial coverage explicitly. Whether the daily quota covers all 25 addresses when no probe queries consume it will be checked on the next measurement day. ADDENDUM 6 October 2026: the gap end of 15 September was wrong. The query from our own network ran only on 15 September; from 16 September to 5 October no run carried a Bing value (D1 bing_ai_index_snapshots, 19 to 26 rows per day, 0 with a value). The gap end is therefore set to 5 October. Since 6 October the query runs daily after the measurement run. On 6 October 15 of 20 addresses returned a value (11 indexed, 4 crawled but not indexed), one address returned an interface error, then the daily quota (ThrottleHost) applied and 3 addresses remained unmeasured. Full coverage of all addresses on one day is therefore not achievable; unmeasured stays unmeasured, not 'not indexed'.
  • Claude channel · 2026-08-01 to 2026-08-02: Addendum 2026-10-05 from the coverage balance of the Q3/2026 validation report: on 1 and 2 August 2026 the Claude web run took place, but all 48 question/model pairs per day ended as error rows without answer text (claude_web_snapshots id 166 and 167, three tiers each n=0, n_error=16). The aggregate excludes both days. Re-measuring is not possible; a gap is not a zero. Source: claude_web_snapshots + claude_web_results snapshot_id 166/167; results.json stage3.coverage_balance.
  • OpenAI channel · 2026-08-18 to 2026-08-19: Measurement-channel outage, SECOND incident (first: 24 Jul-06 Aug): the OpenAI API account ran out of credits again (insufficient_quota, verified by direct test on 19 Aug), 12 days after the top-up of 06 Aug; consumption ~29 search calls/day (gpt-4o-mini-search-preview). Affected: 18 Aug (32 error rows, not retroactively measurable, primary value Gemini-only) and 19 Aug (after the top-up on 19 Aug ~09:40 UTC the stage was re-run = real measurement, no gap). Also fixed on 19 Aug: the live stage aggregation had counted error rows as datapoints (0% cited), depressing the combined value (11.1% instead of ~16.7%); since worker 3fd56929 error rows are no longer datapoints and providers without a valid answer appear as unavailable (a gap is not a zero). Durable prevention: auto-recharge in OpenAI billing (operator).
  • Method · 2026-08-19: METHOD CHANGE (not a gap): the AI-citation measurement (OpenAI/Gemini/Claude batch) runs every 3 days instead of daily from 19 Aug (measurement days 19, 22, 25 Aug ...). Rationale from 50 days of data: day-to-day autocorrelation 0.02 (daily values are noise around a stable level), 3-day means halve the spread, cost drops to a third. The series stays comparable (same 16 questions, providers, scoring); on in-between days the dashboard shows the latest measurement day (date shown explicitly). At the same time the headline was split into three channels (Direct / Saga knowledge / Recommendation); the combined value remains for continuity.
  • Method · 2026-08-19 to 2026-10-07: METHOD CORRECTION (not a gap), fixed on 7 October 2026 before the book release: The headline figure is the simple average of the providers OpenAI, Gemini and Claude (web). If two providers fail on an anchor day, the remaining single value is no longer a combined figure. From 7 October such days carry no headline figure; the single value stays visible per provider. One anchor day is affected: 27 September 2026 (Gemini only, 22.9 %), which had appeared as a headline point in the trend. Days with two of three providers remain in the trend and are drawn as hollow points. The book-release analysis (Q7) relies on OpenAI and Gemini anyway and is not affected.
  • Method · 2026-08-19 to 2026-10-07: METHOD CORRECTION (not a gap), fixed on 7 October 2026 before the book release: Answers that state explicitly that the search for Marin T. Kael returned nothing count as honest non-knowledge (0 points), not as invented details (−3). The rule of 7 October recognised this only for some phrasings; from now on also for “ergeben”, “search”, “identify” and “ascertainable”, and for redirection by the search (“returns mainly results about Pauline Kael”). A mere confusion without any statement about the search remains −3. Same rule for OpenAI, Gemini and Claude. Rescored from 19 August only where the stored excerpt itself proves the statement: OpenAI/Gemini 9 answers (8 from −3 to 0, one from −3 to +1), all Gemini on question D1; Claude (web) 4 answers (19 and 21 Sep Opus D2, 7 Oct Sonnet D2 and Haiku D1). Five Claude answers from 25 Aug to 6 Sep stay unchanged because the excerpt does not contain the original trigger. Measurement days from 19 August re-aggregated. For the book-release analysis the rule applies equally to baseline and effect window.
  • Method · 2026-08-19 to 2026-10-07: METHOD CORRECTION (not a gap), fixed on 7 October 2026 before the book release: An answer referring to the film critic Pauline Kael is a name collision with a real person, not invented information about Marin T. Kael. From now on it is treated like the title collision with the non-fiction book by Mokka Müller: 0 points (status collision) instead of −3. If the answer also gives genuine information about Marin and his book, that is scored as usual. A collision also applies when the answer contains no information about Marin beyond repeating the name. Same rule for OpenAI, Gemini and Claude. Rescored from 19 August only where the stored text itself contains Pauline Kael: Gemini 6 Sep question D1 (−3 to +2; the answer describes Marin correctly and names the possible confusion) and Claude Haiku 19 Sep question D1 (−3 to 0). Five Claude Opus answers from 25 Aug to 6 Sep stay at −3 because their stored excerpt does not contain the original trigger. Measurement days from 19 August re-aggregated. For the book-release analysis the rule applies equally to baseline and effect window.
  • Method · 2026-08-19 to 2026-10-15: METHOD CORRECTION (not a gap), fixed on 15 October 2026 during the effect window: The scoring scheme previously required the author name Marin T. Kael as a mandatory anchor. Answers naming the book correctly but without the author name therefore counted as not found. From now on the book or series title (“Das vierte Feld”, “Prägungen des Reiches”) also counts as an anchor when it is not already part of the question; this applies to all questions except the Direct questions, since only D2 and D3 contain the title. The non-fiction book of the same title by Mokka Müller remains a title collision without points. Same rule for OpenAI, Gemini and Claude. Rescored from 19 August under the same rule: exactly two answers, both on 12 October for question L1 (Gemini 0 to 2, Claude Opus 5.5 0 to 2); no answer in the baseline of the book release is affected, so the rule applies equally to baseline and effect window. Measurement day 12 October re-aggregated.
  • Method · 2026-08-20 to 2026-10-04: METHOD NOTE (not a gap): between 20 August and 4 October 2026 OpenAI and Gemini measured on 30 days outside the three-day cadence in force since 19 August. The cause was a closing step of the measurement run that triggered the full measurement again instead of only recomputing; a fix from 3 September was lost in a later update. Decision of 4 October 2026: the pre-registered cadence applies; from 5 October measurements run on anchor days only (run version 229bf6a8). The 30 extra days remain in the dataset as valid measurements and are flagged as off-schedule; analyses on the anchor-day grid leave them out.
  • Method · 2026-08-22 to 2026-09-03: METHOD CORRECTION (no gap): on the anchor days 22, 25, 28, 31 Aug and 3 Sep, Gemini and OpenAI Search had 32 rows for 16 questions in ai_citation_results (identical answer and score, ~50 s apart). Root cause in the Worker: the workflow step finalize-aggregate re-ran the full live stage ai_citation instead of only reaggregating the snapshot; on non-anchor days the same step produced 16 unplanned rows despite the 3-day cadence. Effect: double weight of the web channels in the aggregation. Correction 3 Sep: duplicate rows removed (oldest per question kept), snapshots reaggregated. Combined value before/after: 22 Aug 11.5/6.9, 25 Aug 8.0/5.0, 28 Aug 12.1/8.5, 31 Aug 12.6/9.0, 3 Sep 9.9/8.8 percent. Report 03 of 19 Aug is unaffected (data through 19 Aug). Worker fix: finalize-aggregate calls reaggregateSnapshot.
  • Claude channel · 2026-08-23: Measurement failure: the claude.ai run of 2026-08-23 wrote all 48 rows (3 model tiers x 16 questions) with error status, so not a single usable answer. The run therefore appears in the aggregate with n=0 and no percentage and enters neither the headline figure nor the trend; a gap is not a zero. 23 Aug was not an anchor day, so the three-day cadence (19, 22, 25 Aug) is unaffected. Consequence for question-level analyses: Claude-Web offers ten instead of eleven repeats per question since 19 Aug. Retroactive measurement is impossible because a measurement always records the state of its own day. Detected 2026-09-07.
  • Documented intervention · 2026-08-27: Documented intervention, NOT a measurement gap: submitted the programme to the third-party curated list DavidHuji/Awesome-GEO (PR #17, paper DOI + CC-BY dataset). First non-self-published mention if merged. Prompted by the 21 Aug expert finding on r/GEO_optimization that the recommendation channel is gated by third-party evidence rather than entity recognition. A second, separately dated intervention follows on 22 Sep (book release).
  • Claude channel · 2026-08-31 to 2026-09-03: Missing measurement for provider Claude (web) on an anchor day: on 2026-08-31 the claude.ai run did not execute because the measurement environment was down for four days, 2026-08-29 to 2026-09-01. The headline figure combined_primary for 2026-08-31 therefore rests on two providers instead of three (OpenAI 22.9%, Gemini 20.8%, result 21.9%). It cannot be measured retroactively; a gap is not a zero. The anchor day 2026-09-03 has no Claude measurement of its own for the same reason; its point carries the Claude measurement of 2026-09-02. Source: claude_web_snapshots against the anchor grid from 2026-08-19.
  • OpenAI channel · 2026-09-03: Measurement channel outage ONGOING, THIRD incident (1st: 24 Jul-6 Aug, 2nd: 18-19 Aug): OpenAI API account out of credits again (openai_quota_exhausted in all 32 openai_search rows of run 30f44ad7 on 3 Sep 04:03 UTC; 31 Aug-2 Sep error-free), 15 days after the top-up of 19 Aug. Usage about 29 search calls per day (gpt-4o-mini-search-preview). Primary value until top-up: Gemini plus Claude batch only; a gap is not a zero (unavailable_llms_v271=[openai_search]). gap_end provisional = reporting day, to be updated after the top-up. ADDENDUM: top-up 3 Sep noon (operator), stage re-run at 12:12 UTC = real value for 3 Sep, no gap anymore; row kept as incident record.
  • Method · 2026-09-04: METHOD NOTE (no gap): Since 4 September 2026 there is a single headline figure: the simple mean of the three providers OpenAI, Gemini and Claude (each as the share of the highest possible rating across all 16 questions, Claude as the mean of its three model tiers). The three question types and the trend are computed from the same basis. Previously, values with a different basis (all models including control models; OpenAI and Gemini pooled) stood next to it; these now appear only as audit values in the methodology card.
  • Claude channel · 2026-09-12: Missing measurement for provider Claude (web) on the anchor day 2026-09-12: the daily run issued all 48 question/model pairs but received a throttling response from the provider for every single one (error code comp-429). None of the 48 rows carries an answer, no web search was triggered in any of them, and response times were 1 to 3 seconds. The aggregate correctly excludes the day (n=0, percent=null per tier); the headline figure combined_primary for 2026-09-12 therefore rests on two providers instead of three. It cannot be measured retroactively; a gap is not a zero. Side finding: the run log and the push reported the run as successful (48 rows scored, daily flag set) although no row carried a measurement. Source: claude_web_snapshots id 196 (run_ts 2026-09-12T06:13:36, total_rows 48, all three tiers n=0 n_error=16) and claude_web_results snapshot_id 196 (48 of 48 status=error).
  • Claude API control channel · 2026-09-15: Partial outage of the Claude API batch audit channel on anchor day 2026-09-15, precursor of the outage from 18 September (entry id 22): for the model claude all 16 questions ended as error rows with the provider notice that the credit balance was insufficient; claude_opus and claude_sonnet returned 16 answers each. The headline figure combined_primary is not affected; the channel only feeds audit values. The channel has been discontinued since 2026-10-04 (entry id 25). Source: ai_citation_results asked_at 2026-09-15 04:30:57 (llm=claude, 16 of 16 status=error).
  • Method · 2026-09-15 to 2026-10-07: METHOD CORRECTION (not a gap), fixed on 7 October 2026 before the book release: (1) The list of key facts in the scoring scheme still contained the old release date of 22 September 2026. Since the postponement on 15 September answers name 8 October 2026 and received no point for it; an answer needs four key facts for the full score. From 7 October the release date counts date-neutrally (22 Sep or 8 Oct), equally for OpenAI, Gemini and Claude. Rescoring from 15 September only where the stored 500-character excerpt itself proves the four key facts: 8 answers from “partial” (2) to “full” (3), all Gemini or OpenAI; measurement days re-aggregated (e.g. 3 Oct: 29.2 % to 31.3 %). Further answers were probably affected too but cannot be proven without the full text and stay unchanged. For the book-release analysis the corrected rule applies equally to baseline and effect window. (2) Full archiving of all answers (requirement of 5 June) had stopped since 22 June because the change was lost when deployments switched to the source code; since 22 June only 500-character excerpts exist. Full archiving resumes from 7 October.
  • Claude channel · 2026-09-16 to 2026-10-06: FINDING, not a gap: between 15 September (direct questions 9 of 9 cited, sources incl. marin-t-kael.de and Wikipedia) and 19 September 2026 (2 of 9), claude.ai web search stopped returning pages about Marin T. Kael. Since then its hits are unrelated pages (film criticism on Pauline Kael, military and library sites), not a single source about the author. OpenAI (Bing search) and Gemini (Google search) find the author unchanged in the same period (direct questions 3 of 3); the website is reachable for Anthropic fetchers and present in Brave Search. The cause therefore lies with the claude.ai search service, not the measurement. Claude values from 19 September are not comparable with earlier values.
  • OpenAI channel · 2026-09-18 to 2026-09-27: Measurement gap, not a zero: from 18 to 27 September 2026 the provider openai_search returned only error rows (160 rows across ten days, 16 per day, reason openai_quota_exhausted; source D1 ai_citation_results status=error). On those days the headline figure combined_primary rested on two of three providers instead of three, and on 27 September on one provider only, because the Claude web channel failed as well (separate entry). Day-to-day movements across this boundary are changes of basis, not measured change. Addendum 29 September 2026: the channel measures again. On 28 September openai_search returned 16 of 16 answers with no error row and with real scoring. The gap is therefore bounded to 18 to 27 September and closed. The cause of the exhaustion remains open; a further outage during the effect window from 8 October cannot be ruled out.
  • Claude API control channel · 2026-09-18 to 2026-10-03: Measurement outage of the Claude API batch control channel (models claude, claude_opus, claude_sonnet) on the anchor days 18, 21, 24 and 27 September 2026. The last batch job on record was submitted on 15 September 2026; on the four anchor days listed no job was submitted and no answer row was written, not even an error row. CAUSE, located in the code: not the channel but the stage runner's accounting. The runner recorded every stage as successful unless it THREW; a stage reporting its own failure as a return value had that value stored unexamined while the outer success verdict prevailed. The run report therefore showed 16 of 16 stages successful on each of those days while the channel was silent. Fixed on 30 September 2026: only an explicit top-level failure verdict counts as a failure, stages without that field are unaffected; covered by a regression test over nine return shapes. EFFECT ON ANALYSIS: none on the headline figure combined_primary, which rests on the web providers OpenAI, Gemini and Claude Web and does not include the API batch. Affected are the audit figures score_percent and by_category, computed across all models: on these four days they rest on two models instead of five and are not comparable with preceding days. The outage coincided with the OpenAI outage of the same period (entry id 17); the two share no cause. NOT RETROACTIVELY MEASURABLE: a batch measurement cannot be dated to a past day. The four anchor days remain a gap, not a zero. ADDENDUM 1 October 2026: The anchor day 30 September 2026 belongs to this gap as well (0 answer rows from the three models). With the accounting fix of 30 September, the stage reported its error text for the first time on that day, verbatim: provider response invalid_request_error, the credit balance of the API account is too low. This identifies the cause of the channel outage itself: exhausted provider credit, not a technical fault. It is documented for 30 September; for 18 to 27 September it is likely but not documented, because the error text was not recorded on those days. The delimitation of effects above is unchanged. ADDENDUM 4 October 2026: The anchor day 3 October 2026 belongs to this gap as well (0 answer rows from the three models); the stage reported the same error text on exhausted credit (pipeline_runs id 0ef2c9cd, stages_failed 1). The delimitation of effects is unchanged.
  • Claude channel · 2026-09-18: Claude Web did not measure on the anchor day 18 September 2026. The daily run left neither a completion marker nor a snapshot row; the measurement took place one day later, on 19 September 2026 06:31 UTC, through the catch-up for a failed measurement day (48 of 48 rows with a value, claude_web_snapshots id 198). The cause of the miss on 18 September can no longer be established; the run log only reaches back to 23 September. EFFECT: the published trend point for 18 September carries the Claude Web measurement of 19 September, so it is not a measurement of that day but a value that arrived later. For the baseline before the book launch, 18 September counts as an off-grid Claude Web measurement (one day late), not as an anchor-day measurement. Found on 1 October 2026 while preparing the Q3 activity report: the running check had counted the day as covered because it treated the late value as a measurement of that day.
  • Method · 2026-09-19 to 2026-10-06: METHOD CORRECTION (not a gap): since 19 September 2026 Claude (claude.ai with web search) often answers the direct questions with “no person named Marin T. Kael found, did you mean Pauline Kael?”. The scoring scheme counted every mention of Pauline Kael as a confusion (−3), even when the answer explicitly reports finding nothing. That is honest non-knowledge and is scored 0 (not_found_disclaimed) from 7 October 2026; a plain confusion without a search statement remains −3. 13 Claude answers from 19 September to 6 October were rescored (before −3, after 0) and the five affected measurement days re-aggregated; raw answers unchanged. Claude value on 6 October: before −6.2 %, after +2.1 %; headline 12.5 % → 15.3 %. Same rule in the measurement run for OpenAI and Gemini (version 5c2f8f41).
  • Documented intervention · 2026-09-22: Documented intervention, NOT a measurement gap. On 2026-09-22 the first volume of the saga becomes available in retail. This is the largest planned intervention of phase 1 and is registered in advance so that the pre/post analysis is not justified after the fact. HYPOTHESIS: retail availability creates, for the first time, third-party machine-readable records (retailer catalogue, library metadata, ISBN registries). Search-augmented models are expected to retrieve these records, so the hit rate in the direct channel (questions D1-D3) should rise earlier than in the recommendation channel (GR1-GR6), which additionally requires reception signals. NULL HYPOTHESIS: no difference between the measurement windows. WINDOWS: baseline 2026-08-23 to 2026-09-21 (10 anchor days of the 3-day cadence), effect window 2026-09-22 to 2026-10-22 (10 anchor days), observation until 2026-12-21 for delayed effects. METRIC: combined_primary per measurement day (web providers OpenAI, Gemini, Claude-Web, equally weighted), additionally split by the three channels direct / saga-knowledge / recommendation. ANALYSIS: pre/post comparison with CUSUM baseline drift subtracted, so an ongoing trend is not read as an effect of the intervention. UNCHANGED: the 16 fixed questions, the provider panel and the 3-day cadence are NOT adjusted for this intervention.
  • Claude channel · 2026-09-24: Beeinträchtigung des Claude-Web-Kanals am Messtag 24.09.2026, am selben Tag nachgemessen. Das Laufzeit-Umfeld des Mess-Werkzeugs war seit dem 22.09.2026 unvollständig: der Programm-Interpreter, mit dem der Tageslauf startet, war im Zuge einer unabhängigen Aufräumung eines anderen Arbeitsbereichs verschoben worden. Der planmäßige Lauf am 24.09. um 08:10 brach deshalb sofort ab, ohne eine einzige Frage zu stellen, und ohne dass eine Fehlermeldung an eine überwachte Stelle ging. Beleg: Fehlerausgabe des Tageslaufs, Abbruchcode 126, Meldung "No such file or directory" zum Interpreter-Pfad; kein Tagesnachweis für den 24.09. UMFANG: Betroffen ist genau ein Messtag (24.09.). Die Tage 22. und 23.09. sind nach der 3-Tage-Kadenz ohnehin keine Messtage des Kanals; ihre Trendpunkte tragen planmäßig die Messung vom 21.09. FOLGE FUER DIE KOPFZAHL: Zusammen mit dem gleichzeitigen Ausfall des Anbieters OpenAI ruhte die Kopfzahl am 22., 23. und 24.09. auf nur EINEM Anbieter (Gemini) statt auf dreien. Der sichtbare Anstieg von 5,1 (23.09.) auf 20,8 (24.09.) ist daher ein Wechsel der Rechengrundlage und kein gemessener Zugewinn. Die Ergebnisseite weist die Zahl der tragenden Anbieter je Tag aus. BEHEBUNG: Der Kanal wurde am 24.09. auf einen vorhandenen Interpreter umgestellt und die Tagesmessung um 16:59 Ortszeit nachgefahren, rund achteinhalb Stunden später als planmäßig. Diese Abweichung der Tageszeit ist bei der Auslegung des Messpunkts zu berücksichtigen. Zusätzlich prüft die Integritätsprüfung seither vor jedem Messtag, ob das Erhebungswerkzeug überhaupt startfähig ist und ob der Tagesnachweis vorliegt; ein stiller Ausfall dieser Art wird damit am selben Tag sichtbar.
  • Claude channel · 2026-09-27: Measurement outage of the Claude (web) provider on anchor day 2026-09-27. The daily run fired all 48 question/model pairs but received a throttling response (error code comp-429) to every single one. None of the 48 rows carries an answer, no web search was triggered, response times were 1 to 3 seconds. Source: claude_web_snapshots id 201 and claude_web_results snapshot_id 201 (48 of 48 status=error). Re-measuring is not possible; a gap is not a zero. CONSEQUENCE FOR THE HEADLINE FIGURE, and it points in the unfamiliar direction: because the OpenAI provider has also been failing since 18.09., combined_primary on 27.09. rests on only ONE provider (Gemini). The published value rises from 9.4 per cent (26.09.) to 22.9 per cent (27.09.) - this is NOT a measured gain. On 26.09. the Claude measurement of 24.09. still entered the mean at 0.0 per cent; on 27.09. that contribution drops out entirely, leaving Gemini alone to form the headline figure. Gemini itself moved only from 18.8 to 22.9 per cent. The jump of 13.5 percentage points is therefore mostly a change of basis. A failed measurement run has a stronger effect here than no run at all, because it displaces the provider value carried previously. ACTION 2026-09-28: until then the results page named the change of basis fixedly as a decline, because the note was written on a day when the dropout pushed the figure down; it now names the movement without a direction (DE and EN).
  • Claude channel · 2026-10-03: Measurement outage of the Claude (web) provider on anchor day 2026-10-03, same pattern as on 27.09. (entry id 21). The daily run fired all 48 question/model pairs and received a throttling response (error code comp-429) to each; the whole run took just under four minutes instead of about twenty, no row carries an answer. Source: claude_web_snapshots id 203 (run_ts 2026-10-03T06:13:28, total_rows 48) and claude_web_results snapshot_id 203 (48 of 48 status=error, 16 in each of the three tiers). Re-measuring is not possible; a gap is not a zero. CONSEQUENCE FOR THE HEADLINE FIGURE: combined_primary on 03.10. rests on OpenAI and Gemini instead of three providers. The published value rises from 13.9 per cent (02.10., three providers, Claude value carried over from 30.09.) to 29.2 per cent (03.10., two providers). As on 27.09., the jump is wholly or mostly a change of basis, not a measured gain: the Claude contribution that held the mean down drops out. Source: /api/timeseries by_provider. Two of the last three anchor days thus lack a Claude measurement (27.09., 03.10.).
  • Method · 2026-10-04: METHOD CHANGE (not a gap): the control channel via the Claude API (models claude, claude_sonnet, claude_opus, without web search) is discontinued as of 4 October 2026. It never entered the headline figure and had returned no answers since 15 September (entry 22). Claude is measured exclusively through claude.ai with web search (three model tiers, headline provider). At the same time the claude.ai run was hardened: after the outages of 27 September and 3 October (48 throttling responses each, because the usage limit of the measurement account was exhausted until its reset the same afternoon) the run now checks the limit first, aborts after three consecutive throttling responses and is retried up to six times on the same day. A run without enough values is no longer booked as a measurement day; the actual measurement time is recorded in run_ts.
  • Method · 2026-10-07: METHOD CHANGE (not a gap): from the next measurement day (9 October 2026) Claude is measured with the newest Opus model on claude.ai (currently Claude Opus 5.5), through the subscription, with web search and in an incognito chat without history or memory. Until 6 October three older model tiers ran (Haiku 4.5, Sonnet 4.6, Opus 4.8) in normal chats. Reason: since about 16 September the older models gave up after a first unrelated search hit (see finding entry claude_web 16 Sep to 6 Oct); a single probe on 7 October with Opus 5.5 in an incognito chat found the author via the website and his own channels. The Claude series has a break at this point; values before and after are not directly comparable.
  • Documented intervention · 2026-10-07: AMENDMENT TO THE PRE-REGISTRATION of the book-release intervention (entry id 18), fixed on 7 October 2026 BEFORE the event on 8 October 2026. It is prompted by measurement changes of 7 October that touch the commitment “the provider panel is not adjusted”; they are justified by measurement problems (entries claude_web 16 Sep to 6 Oct and method_claude_modell), not by interim results. (1) PRIMARY ANALYSIS only on the providers whose panel is unchanged since 19 August: OpenAI search and Gemini, headline as the simple mean of these two per anchor day, plus the three channels Direct / Saga knowledge / Recommendation. Baseline as registered 8 Sep to 7 Oct 2026: Gemini on 10 anchor days, OpenAI on 6 (9, 12, 15, 30 Sep, 3, 6 Oct; outage 18 to 27 Sep registered). Effect window 8 Oct to 7 Nov 2026, observation until 6 Jan 2027. Hypothesis, null hypothesis and analysis (before/after with CUSUM baseline drift removed) unchanged. (2) CLAUDE SECONDARY AND DESCRIPTIVE ONLY: from 7 October Claude is measured with the newest Opus model in an incognito chat; the earlier series (Haiku 4.5, Sonnet 4.6, Opus 4.8) is not comparable. The only baseline of the new configuration is a single measurement on 7 October 2026 before release (outside the three-day grid, for this purpose only); then anchor days from 9 October. No significance judgement for Claude. (3) EARLY AVAILABILITY: paperback and hardcover have been orderable since 30 September 2026; official release and ebook on 8 October. In addition to the registered baseline, a sensitivity baseline 8 Sep to 29 Sep without early availability is reported. (4) NO EFFECT ON THE PRIMARY ANALYSIS from the scoring correction of 7 October (affected only Claude rows 19 Sep to 6 Oct) or from showing the trend only on anchor days (the analysis uses anchor days anyway).
  • Documented intervention · 2026-10-07: SECOND AMENDMENT TO THE PRE-REGISTRATION of the book release (entries id 18 and intervention_book_launch_amendment), fixed on 7 October 2026 before the event, without knowledge of effect data. (a) Correction to point 4 of the first amendment: the release-date correction in the scoring scheme (entry method_scorer_termin) also affects OpenAI and Gemini (8 answers rescored). Because the baseline could only be partly rescored (evidence only from 500-character excerpts) while the effect window is fully scored under the new rule, the point-based Direct channel may be biased upwards in the comparison. (b) Therefore the HIT RATE is added as a robustness metric: share of answers that correctly name the author (score above 0), per provider and channel. It does not depend on the threshold between partial and full citation. An effect in the Direct channel is only reported if it appears in points AND in the hit rate. (c) Analysis details fixed before the data: baseline drift per provider as a linear slope over all anchor days from 19 August 2026; effect per channel as the mean of provider effects (OpenAI, Gemini) with a 95 % bootstrap over anchor days (10,000 draws, fixed seed); time of first deviation per channel as the first alarm of a one-sided CUSUM (k = 0.5, h = 5) within the effect window. The last anchor day in the effect window is 5 November 2026.
  • Documented intervention · 2026-10-07: THIRD AMENDMENT TO THE PRE-REGISTRATION of the book release, fixed on 7 October 2026 before the event and before the first anchor day of the effect window (9 Oct), without effect data. Refines part (b) of the second amendment: the Direct-channel hit rate is already 92.2 percent in the baseline; at most 7.8 percentage points remain up to 100 percent, while the minimum reliably detectable shift is 15.7. The rule “effect only if points AND hit rate are significant” could therefore never confirm an increase in the Direct channel. New: in the Direct channel the hit rate serves as a sign check. A Direct effect in points is reported if its interval excludes zero and the hit-rate estimate has the same sign; if the sign contradicts, the effect is reported as not robust. In all other channels the hit rate remains a full robustness metric as in the second amendment.
  • Documented intervention · 2026-10-08: Dokumentierter Eingriff, KEIN Messausfall. ERSETZT den Eintrag vom 22.09.2026 (id 12), der überholt ist: Der Erscheinungstermin von Band I wurde am 15.09.2026 öffentlich vom 22.09. auf den 08.10.2026 verschoben (Quelle: Termin-Hinweisseite der Website, Konfigurationswert releaseDate). Die alte Vorregistrierung hätte ab dem 22.09. ein Wirkungsfenster gemessen, in dem der Eingriff gar nicht stattfindet - ein Nullbefund wäre fälschlich als ausbleibende Wirkung des Erscheinens berichtet worden. Die Korrektur erfolgt VOR dem Ereignis und ist allein durch die Terminverschiebung begründet, nicht durch Zwischenergebnisse. UNVERAENDERT gegenüber id 12 bleiben Hypothese, Nullhypothese, Kennzahl und Auswertung: HYPOTHESE: Handelsverfügbarkeit erzeugt erstmals von Dritten geführte, maschinenlesbare Nachweise (Händler-Katalog, Bibliotheks-Metadaten, ISBN-Register); erwartet wird, dass such-gestützte Modelle diese Nachweise abrufen und die Trefferquote im Direkt-Kanal (D1-D3) früher steigt als im Empfehlungs-Kanal (GR1-GR6). NULLHYPOTHESE: kein Unterschied zwischen den Messfenstern. KENNZAHL: combined_primary je Messtag (OpenAI, Gemini, Claude-Web, gleichgewichtet), zusätzlich getrennt nach Direkt / Saga-Wissen / Empfehlung. AUSWERTUNG: Vorher-Nachher-Vergleich mit abgezogener CUSUM-Grundliniendrift. NEU DATIERT: Grundlinie 08.09.-07.10.2026, Wirkungsfenster 08.10.-07.11.2026, Beobachtung auf verzögerte Effekte bis 06.01.2027. VORBEHALT: Die Grundlinie ist durch den OpenAI-Ausfall ab 18.09. (siehe Eintrag openai_search) auf zwei Anbieter verdünnt. Solange der Anbieter fehlt, ist der Vorher-Nachher-Vergleich auf der vorregistrierten Drei-Anbieter-Basis nicht auswertbar; die Wiederherstellung des Anbieters vor dem 08.10. ist Voraussetzung für die Auswertung. Anbieter-Panel, 16 feste Fragen und 3-Tage-Kadenz werden für den Eingriff NICHT angepasst.
  • Method · 2026-10-09: METHOD DEFINITION (not a gap), fixed on 7 October 2026 before the book release: From the anchor day 9 October 2026 the provider Claude is measured with all three model families, each the newest model available on claude.ai of Opus, Sonnet and Haiku, in an incognito chat with web search. Each model receives the same 16 questions as OpenAI and Gemini. The value of the provider Claude is the simple mean of the three models; the models are reported individually with the same three question types. Until 6 October these were fixed older tiers (Opus 4.8, Sonnet 4.6, Haiku 4.5); on 7 October only Opus 5.5 ran once. The change of model versions alters the Claude values independently of the book release; the pre-registered analysis of the release therefore relies on OpenAI and Gemini and reports Claude descriptively only.
  • Method · 2026-10-09 to 2027-01-06: METHOD DEFINITION (not a gap), fixed on 7 October 2026 before the book release: If the provider OpenAI fails on an anchor day because its quota is exhausted, OpenAI is re-measured once for that anchor day as soon as the quota suffices again, at the latest 36 hours after the run started (same limit as for Claude). Only the 16 OpenAI questions are re-asked, with the same model; Gemini is not asked again. The answers carry their real timestamp and count for the anchor day of their run. If the re-measurement does not succeed within the limit, the day remains a gap for OpenAI (not a zero value) and is recorded here. For the book-release analysis the rule applies in the effect window; the baseline contains no re-measurement.
  • Method · 2026-10-09: METHOD NOTE (not a gap), recorded on 9 October 2026: On the anchor day 9 October, Claude Haiku was measured with Haiku 5.5 for the first time. The Claude baseline of 7 October still used Haiku 4.5, because 5.5 was not yet available then. Opus 5.5 and Sonnet 5.5 are the same models on both days. The Haiku comparison between baseline and anchor day therefore mixes the book release with the model change. It is reported descriptively only and with this caveat. The rule in entry method_claude_modelle (newest model of each family) is unchanged, and the pre-registered analysis still relies on OpenAI and Gemini.
  • Method · 2026-10-09: METHOD NOTE (not a gap): Under the rule of 7 October 2026 the provider Claude is measured with the newest model of the Opus, Sonnet and Haiku families. Since the anchor day 9 October 2026 that is Haiku 5.5 for Haiku; the baseline of 7 October still used Haiku 4.5 (Opus 5.5 and Sonnet 5.5 unchanged). Comparisons of the Haiku values with the baseline therefore include the model change. The pre-registered analysis of the book release relies on OpenAI and Gemini and is not affected.
  • Measurement channel · 2026-10-10 to 2026-10-12: Partial Common Crawl measurement: the Common Crawl index API returned server errors (HTTP 521) at the scheduled time (04:00 UTC) on 10, 11 and 12 Oct 2026. Each day the measurement was repeated in the afternoon; on 12 Oct only 1 of 12 queries was answered even then, so no inclusion rate exists for that day (empty, not zero). Since 12 Oct a run without a single answered query counts as failed and writes no row.
  • Measurement channel · 2026-10-13: Delayed Common Crawl measurement: on 13 Oct 2026 the Common Crawl index API answered none of the 12 queries at the scheduled time (04:00 UTC, HTTP 521). The run therefore counted as failed and wrote no row. The measurement was repeated the same day at 16:50 UTC: 10 of 12 queries answered, 8 addresses included, 2 queries unanswered. The value for that day comes from this repeat.
  • Measurement channel · 2026-10-14: Partial Common Crawl measurement: on 14 Oct 2026 the Common Crawl index API returned a server error (HTTP 521) at the scheduled time (04:00 UTC) and the run wrote no row. The measurement was repeated the same day at 16:59 UTC: the domain is in the index, but only 4 of 12 queries were answered (3 addresses included, 8 queries unanswered due to overload). There is therefore no inclusion rate for that day (empty, not zero).
  • Measurement channel · 2026-10-16: Delayed Common Crawl measurement: on 16 Oct 2026 the Common Crawl index API answered none of the 12 queries at the scheduled time (04:00 UTC). The measurement was repeated the same day at 16:51 UTC: 8 of 12 queries answered, 6 addresses included, 4 queries unanswered. The value for that day comes from this repeat.
  • Measurement channel · 2026-10-18: Partial Common Crawl measurement: on 18 Oct 2026 the Common Crawl index API answered none of the 12 queries at the scheduled time (04:00 UTC). The measurement was repeated the same day at 19:52 UTC: only 5 of 12 queries answered (4 addresses included, 7 queries unanswered). There is therefore no inclusion rate for that day (empty, not zero).
  • Measurement channel · 2026-10-19: Partial Common Crawl measurement: on 19 Oct 2026 the Common Crawl index API answered none of the 12 queries at the scheduled time (04:00 UTC). The repeat at 16:51 UTC received only 1 of 12 answers (1 address included, 11 queries unanswered). Further evening repeats did not start because the retry then only ran when the day had no row at all; this was fixed on 20 Oct. There is therefore no inclusion rate for that day (empty, not zero).
  • Measurement channel · 2026-10-20: Partial Common Crawl measurement: on 20 Oct 2026 the Common Crawl index API answered only 2 of 9 queries at the scheduled time (04:00 UTC) (1 address included, 1 not included, 7 queries failed with server errors 503, 504 or 521 or a timeout). No more complete measurement was obtained by the end of the day; the existing row was kept unchanged. There is therefore no inclusion rate for that day (empty, not zero).
  • Measurement channel · 2026-10-21: Partial Common Crawl measurement: on 21 Oct 2026 the Common Crawl index API answered only 3 of 12 queries at the scheduled time (04:00 UTC) (2 included, 1 not included, 9 queries failed with server errors 503, 504 or 521 or a timeout). No more complete measurement was obtained by the following day; the existing row was kept unchanged. There is therefore no inclusion rate for that day (empty, not zero).
  • Measurement channel · 2026-10-22: Common Crawl outage: on 22 Oct 2026 the Common Crawl index listing was unreachable at the scheduled time (04:00 UTC) (server error 521); an evening re-run (17:20 UTC) failed as well (server error 520). There is no measurement for that day (a gap, not zero). The cause lies with Common Crawl.
  • Measurement channel · 2026-10-23: Delayed partial Common Crawl measurement: on 23 Oct 2026 the Common Crawl index API answered none of the 12 queries at the scheduled time (04:00 UTC) and the run wrote no row. The measurement was repeated the same day at 17:20 UTC: 7 of 12 queries answered (1 address included, 6 not included, 5 queries failed with server errors 504 or 521 or a timeout). The repeat already ran against the new crawl CC-MAIN-2026-43 (until 21 Oct: CC-MAIN-2026-39); the inclusion rate for that day refers to the new crawl and is not directly comparable with earlier values.
  • Gemini channel · 2026-10-24: Gemini outage on anchor day 24 Oct 2026: the Gemini API rejected all 16 questions (response 402, the measurement account had run out of credit). The pipeline initially scored the empty answers as “not found”; on the same day they were flagged as errors and do not count. There is no Gemini measurement for that day (a gap, not zero). The combined value for the day rests on two providers (OpenAI and Claude) and is drawn hollow in the trend. Since 24 Oct, failed API responses are recorded directly as errors.
  • Measurement channel · 2026-10-24: Delayed partial Common Crawl measurement: on 24 Oct 2026 the Common Crawl index listing was unreachable at the scheduled time (04:00 UTC) (server error 521) and the run wrote no row. The measurement was repeated the same day at around 17:20 UTC: 7 addresses checked, 2 included, 5 without an answer. It refers to crawl CC-MAIN-2026-43 and is not directly comparable with values up to 21 Oct (CC-MAIN-2026-39). The cause lies with Common Crawl.
  • Measurement channel · 2026-10-26: Partial Common Crawl outage: on 26 Oct 2026 the Common Crawl index listing was unreachable at the scheduled time (04:00 UTC) (server error 521). An evening re-run (17:30 UTC) completed, but 8 of 12 queries failed due to overload. The domain is present in index CC-MAIN-2026-43; a per-page inclusion rate is not meaningful for that day (a gap, not zero). The cause lies with Common Crawl.
  • Gemini channel · 2026-10-27: Gemini outage on anchor day 27 Oct 2026: the Gemini API again rejected all 16 questions (response 402, the measurement account had run out of credit, as on 24 Oct). The answers are recorded as errors and do not count. There is no Gemini measurement for that day (a gap, not zero). The combined value for the day rests on two providers (OpenAI and Claude) and is drawn hollow in the trend.
  • Measurement channel · 2026-10-27: Partial Common Crawl outage: on 27 Oct 2026 the Common Crawl API answered none of the 12 queries at the scheduled time (04:00 UTC) (server error 521). An evening re-run (17:31 UTC) completed; 4 of 12 queries failed due to overload. The domain is present in index CC-MAIN-2026-43; the inclusion rate for that day rests only on the answered pages and has limited meaning. The cause lies with Common Crawl.
  • Measurement channel · 2026-10-28: Common Crawl outage: the Common Crawl index overview was unreachable at the scheduled time on 28 Oct 2026 (04:00 UTC) (server error 521); an evening re-run failed as well. There is no measurement for that day; the gap is not a zero value. The cause lies with Common Crawl. Addendum 29 Oct 2026: a further re-run on 28 Oct at 21:51 UTC did write a measurement after all (9 of 12 addresses answered, 2 of them in the index, 3 with server error 504). The day is therefore partially measured rather than missing; the three unanswered addresses are a gap, not a zero value.

What will be analysed next

The methodology note foresees further analyses. They appear here only once enough real measurements exist.

  • Deviation from the starting level · lasting shifts per provider shown above since 4 Sep 2026
  • Reliability of the measurement · How similar is the answer when the same question is asked again? shown above since 8 Sep 2026
  • Effect of single events · What changes after the book release or after an entry in knowledge bases? from 8 Oct 2026
  • Response time of search systems · How long until new information shows up in the answers? in preparation

Data and methodology

All measurements are freely available and can be recomputed.

Audit values and calculation rules (for experts)
  • Headline figure. Simple mean of the three providers OpenAI, Gemini and Claude, each as the share of the highest possible rating across all 16 questions; Claude counts as one provider: the simple mean of its three model families Opus, Sonnet and Haiku, since 9 October 2026 the newest model of each family on claude.ai with web search in an incognito chat (before that fixed older model tiers; on 7 October a single Opus measurement). All three providers and all three Claude models receive the same 16 questions; the individual figures are shown further down. The three question types in the first card come from the same answers, and the trend shows the same figure per measurement day.
  • Repeated answers. If the same question was answered more than once within a measurement run, since 4 September 2026 the answer closest to the scheduled measurement time counts. The rule was applied retroactively to all measurement days. Failed requests are not data points.
  • Audit values of the latest run (different basis, for cross-checking only): OpenAI and Gemini pooled, all answers weighted equally 29.2 % · all models including the control models without web access 29.2 % · control models without web access only — · by question type (OpenAI and Gemini pooled): Direct 88.9 %, Genre 0.0 %, LongTail 50.0 %, CompCluster 0.0 %, Research 0.0 %, GenreRecommend 16.7 %.

Measurements are updated automatically · page as of 2026-10-29