Fact Hallucination
Detects factual claims that appear fabricated, such as wrong dates for well-known events, incorrect attributions, or scientific facts that contradict established knowledge.
Technical description
Identifies factual assertions in text (dates of events, named attributions, scientific claims, historical facts) and checks them against a curated knowledge base of commonly hallucinated facts. Focuses on: wrong attribution of discoveries/theories to researchers, incorrect dates for well-known scientific milestones, contradictions with established scientific consensus, and implausible quantitative claims about well-documented phenomena.
How it works
Layer 1 (deterministic): Extracts factual claims (attributions, dates, quantitative assertions) using pattern matching. Checks claims against a knowledge base of commonly hallucinated facts. Validates dates against known timelines. Cross-references attributions against a database of discoveries and their actual originators. Flags claims that contradict established facts.
Why this matters
AI models can state incorrect facts with the same confidence as correct ones, creating convincing but wrong claims. In academic writing, factual hallucinations about well-established science can undermine a paper's credibility and mislead readers. Common examples include attributing discoveries to wrong scientists or citing incorrect dates for landmark studies.
Score thresholds
- 0-1
- No factual errors detected against knowledge base
- 2-3
- Some claims could not be verified
- 4-5
- Multiple factual claims contradict established knowledge
Limitations
The knowledge base is necessarily incomplete and focuses on commonly hallucinated facts. Emerging or contested scientific findings may be flagged incorrectly. Domain-specific facts outside the knowledge base cannot be verified.
References
- Ji Z, Lee N, Frieske R, Yu T, Su D, Xu Y, Ishii E, Bang Y, Madotto A, Fung P. (2023). Survey of hallucination in natural language generation. ACM Computing Surveys
- Rahman SS, Islam MA, Alam MM, Zeba M, Rahman MA, Chowa SS, Raiaan MAK, Azam S. (2025). Hallucination to truth: a review of fact-checking and factuality evaluation in large language models. arXiv preprint arXiv:2508.03860
- Kim H, Yu H, Yi H. (2026). The LLM fallacy: misattribution in AI-assisted cognitive workflows. arXiv preprint arXiv:2604.14807
- Gershman SJ, Ullman TD. (2023). Causal implicatures from correlational statements. PLoS One
- Boutron I, Dutton S, Ravaud P, Altman DG. (2010). Reporting and interpretation of randomized controlled trials with statistically nonsignificant results for primary outcomes. JAMA