Fact or Fiction
Fact or Fiction
Ask any question, including odd ones. You get a percentage, a clear call of more or less than 50%, the working, and the sources that produced it. If nothing matches, the score stays at 50% — nothing is invented.
Likelihood
H010 Bayoumi's assistance was un-tasked hospitality (competing explanation)
51%
Equal to 50% — the sources do not tip either way
The score is 51% — more than 50%. Supporting sources currently outweigh contradicting sources after quality and confidence are applied.
How 51% was calculated
Start at 50%. Move by half of the net source score after uncertainty. Net source score is 0.08 (from −1 contradict to +1 support). Uncertainty is 82%. So 50% + 50% × 0.08 × 18% remaining certainty = 51%.
Supporting sources
6
Weighted strength 1.18
Contradicting sources
4
Weighted strength 1.01
No stance yet
30
Pulls the score toward 50% · 9.73
Uncertainty
82%
Share of the file that is unlabelled or missing
Working
start at 50% + half of (net source score × remaining certainty)
0.5 + 0.5 × 0.08 × (1 − 0.82) = 0.507
This percentage is calculated from the sources listed below — it is a score, not a court finding. Official origin does not add extra weight. Independent origin does not subtract weight. Two papers from the same group are one cluster, not two independent confirmations.
Reasoning
Step 1 · Match the question
Closest stored question: H010 — Bayoumi's assistance was un-tasked hospitality (competing explanation). Yes/no labels are taken from sources already linked to that question. Also close: H009, H007, H013.
Step 2 · Find matching sources
40 source(s) matched the wording. 5 further source(s) already linked to the stored question were included even if they did not contain the search words. 6 matching claim(s) contributed inherited stances.
Step 3 · Assign support or contradiction without inventing
5 labelled from stored question links, 6 from claims, 0 labelled automatically (capped, marked, not saved as human review), 29 left with no stance.
Step 4 · Weight each source
Each source contributes strength = (quality / 5) × confidence × how strongly it agrees or disagrees. Support strength 1.18, contradict strength 1.01, no-stance strength 9.73. A zero on chain of custody still lowers the mean and stays visible.
Step 5 · Turn that into a percentage
Start at 50%. Move up if support outweighs contradiction, down if the reverse. Unlabelled sources shrink the movement, so a thin file stays near 50%. Working: 0.5 + 0.5 × 0.08 × (1 − 0.82) = 0.507.
Step 6 · What this number is not
This percentage is calculated from the sources listed below — it is a score, not a court finding. Official origin does not add extra weight. Independent origin does not subtract weight. Two papers from the same group are one cluster, not two independent confirmations.
What is still missing
- 3 source(s) score zero on at least one quality check (shown on each card). Those zeros are kept visible and are not averaged away.
- 6 source(s) are unverified, inactive, or recorded as not retrieved. A missing file is a gap, not a finding against the question.
- 30 relevant source(s) have no stance yet. They increase uncertainty and pull the percentage toward 50%; they are not counted as support or contradiction.
- A second stored question (H009) also matches this wording. The percentage below is for H010 only — open the other question to compare. Do not average the two numbers.
Closest stored question
H010 · Bayoumi's assistance was un-tasked hospitality (competing explanation)competing · match 41.7
Related questions
Same wording can map to more than one stored question. Each has its own percentage — do not average them.
Matching claims
- verifiedCLM-001
Omar al-Bayoumi provided housing and banking assistance to Nawaf al-Hazmi and Khalid al-Mihdhar in San Diego in February 2000.
- disputedCLM-010
Bayoumi's assistance was ordinary Muslim hospitality with no tasking.
- partially_supportedCLM-003
Omar al-Bayoumi was a paid cooptee of Saudi GIP reporting via Ambassador Bandar.
- contradictedCLM-004
Bayoumi did not knowingly assist Islamist extremists.
- contradictedCLM-005
Fahad al-Thumairy provided no assistance to the two operatives.
- indeterminateCLM-008
Bayoumi had advance knowledge that the 9/11 attacks would occur.
Sources that support this
6Bayoumi locates apartment, co-signs lease, opens bank account
9/11 Commission Report · 2004-07-22
Bayoumi performed specific, documented housing and banking tasks for the two men in early February 2000.
hypothesis link · human_seed link to H010 (seeded): Immediate reimbursement of the check is consistent with hospitality, not a covert payroll.
Parkwood manager on Bayoumi's lease role (later interview)
BBC reporting on Parkwood apartments and 2024 litigation · 2026-08-29
A property manager later described Bayoumi as handling the rental for the two men.
claim stance · Inherited from matching claim CLM-001.
Commission character assessment of Bayoumi
9/11 Commission Report · 2004-07-22
The 2004 Commission published a negative finding on Bayoumi's knowing extremist involvement.
hypothesis link · human_seed link to H010 (seeded): Character assessment of an unlikely clandestine actor.
Commission: no evidence Thumairy assisted the two operatives
9/11 Commission Report · 2004-07-22
2004 Commission published a negative finding on Thumairy assistance.
claim stance · Inherited from matching claim CLM-005.
FBI 2017: Bayoumi reporting channel through Bandar to GIP
FBI materials released under Executive Order 14040 · 2017-06-14
FBI analysis describes Bayoumi as a community collector reporting via the ambassador.
claim stance · Inherited from matching claim CLM-003.
KSM: operatives told to pose as students and seek mosque help
9/11 Commission Report · 2004-07-22
The Commission records a KSM claim that the two were instructed to seek mosque assistance and that AQ had no California agents.
hypothesis link · human_seed link to H010 (seeded): Operatives were told to seek mosque help, so a helper may appear without tasking.
Sources that contradict this
4FBI 2017: Bayoumi paid as GIP cooptee via Ambassador Bandar
FBI materials released under Executive Order 14040 · 2017-06-14
An official FBI analytical document asserts Bayoumi was a paid GIP cooptee through Bandar, 1998–2001.
hypothesis link · human_seed link to H010 (seeded): Paid cooptee status undercuts 'just a gregarious student-employee.'
Judge Daniels 2024: not 'just an innocent participant'
In re Terrorist Attacks on September 11, 2001 (S.D.N.Y.) · 2024-08-01
A U.S. district judge in 2024 drew a reasonable-inference finding that Bayoumi's housing help was tasked by the Saudi government.
hypothesis link · human_seed link to H010 (seeded): Court rejected the innocent-participant framing.
FBI 2017: Commission-era non-confirmation, later confirmation of intel role
FBI materials released under Executive Order 14040 · 2017-06-14
FBI 2017 text asserts the intelligence-role allegation was unconfirmed in 2004 and is now confirmed.
claim stance · Inherited from matching claim CLM-004.
FBI: Thumairy tasked an associate; 'two very significant people'
FBI materials released under Executive Order 14040 · 2021-09-11
Declassified FBI reporting asserts Thumairy tasked help and described the pair as very significant before the attacks.
claim stance · Inherited from matching claim CLM-005.
Sources with no stance yet
30FBI analytical statement: 50/50 chance Bayoumi had advance knowledge
FBI materials released under Executive Order 14040 · 2017-06-14
An FBI analytical product assigned even odds to Bayoumi's advance knowledge of the attacks.
claim stance · Inherited from matching claim CLM-008.
Commission: UA93 crashed near Shanksville at 10:03:11 after a passenger revolt
9/11 Commission Report · 2004-07-22
UA93 impacted a field in Somerset County, Pennsylvania, at 10:03:11. Official transcription of the CVR describes a passenger counterattack.
unclassified · Retrieved as relevant; no inherited polarity. Unclassified mass raises uncertainty rather than inventing support or contradiction.
Hazmi suspected Bayoumi was a Saudi spy
9/11 Commission Report · 2004-07-22
Commission reports Hazmi expressed suspicion that Bayoumi was a Saudi spy.
unclassified · Retrieved as relevant; no inherited polarity. Unclassified mass raises uncertainty rather than inventing support or contradiction.
Bayoumi initially denied knowing Hazmi and Mihdhar
9/11 Commission Report · 2004-07-22
Bayoumi's first interview denied a relationship he later described and that documents corroborate.
unclassified · Retrieved as relevant; no inherited polarity. Unclassified mass raises uncertainty rather than inventing support or contradiction.
Thumairy denials contradicted by witnesses and telephone records
9/11 Commission Report · 2004-07-22
Commission reports a contradiction between Thumairy's denial of knowing Bayoumi and other records.
unclassified · Retrieved as relevant; no inherited polarity. Unclassified mass raises uncertainty rather than inventing support or contradiction.
Hazmi leaves San Diego with Hanjour, December 2000
9/11 Commission Report · 2004-07-22
Hazmi's San Diego residence ends mid-December 2000.
unclassified · Retrieved as relevant; no inherited polarity. Unclassified mass raises uncertainty rather than inventing support or contradiction.
Bayoumi video of the U.S. Capitol and other sites
FBI materials released under Executive Order 14040 · 2022-03-01
Video associated with Bayoumi includes Washington, D.C. landmarks.
unclassified · Retrieved as relevant; no inherited polarity. Unclassified mass raises uncertainty rather than inventing support or contradiction.
1 February 2000 restaurant encounter — chance or design unknown
9/11 Commission Report · 2004-07-22
A lunch on 1 February 2000 involving Bayoumi, Hazmi, and Mihdhar is documented because Bayoumi reported it.
unclassified · Retrieved as relevant; no inherited polarity. Unclassified mass raises uncertainty rather than inventing support or contradiction.
Topics
Day-of events, engineering questions, process failures, and foreknowledge leads.