Service — Factual Accuracy

Hallucination Detection

Claim-by-claim verification of AI outputs against source documents or domain knowledge. Our ML pipeline auto-extracts every factual claim; expert annotators verify each one. Delivered with a hallucination rate breakdown by category and severity — so you know exactly what your model gets wrong and how badly.

Claim-by-Claim
Every factual claim extracted and individually verified — not just document-level review
4-Tier
Severity classification: Verified, Minor, Significant, and Critical hallucination
5 Days
Turnaround on free 50-output audit — no commitment required
Domain
Expert verifiers matched to your domain — medical, legal, financial, general
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Claim ExtractionFact VerificationSeverity ScoringSource AttributionDomain Expert ReviewFabrication DetectionRAG FaithfulnessCitation AccuracyClaim ExtractionFact VerificationSeverity ScoringSource AttributionDomain Expert ReviewFabrication Detection
What It Is

AI models confabulate — claim-level verification finds exactly where

Hallucination is not a vague quality problem — it is a specific, measurable failure: an AI model generates a factual claim that is false, unsupported, or fabricated. Claim-by-claim verification is the only way to measure hallucination rate with the precision needed to act on it.

When an AI model says "The Indian Companies Act 2013 requires all directors to hold a minimum of one share," that sentence contains a specific, verifiable factual claim. It is either correct or incorrect. Document-level quality review cannot reliably catch this — it requires someone with legal expertise to check that specific claim against the correct statute text.

Most AI evaluation approaches rate output quality holistically — coherence, fluency, helpfulness — without systematically extracting and verifying individual factual claims. This means a response rated 4/5 for "overall quality" can contain multiple significant factual errors that the quality rater simply missed or was not equipped to catch.

Our hallucination detection pipeline inverts this. We first use an LLM-based claim extractor to decompose every AI output into its individual factual claims — typically 3–15 claims per response. Each claim is then routed to a domain expert for verification against authoritative sources. Claims are classified into four severity tiers: Verified (correct), Minor Inaccuracy (partially correct), Significant Hallucination (meaningfully wrong), and Critical Fabrication (dangerous or completely invented). You receive a per-claim report, an overall hallucination rate, and a severity breakdown — actionable data, not an impressionistic quality score.

Why does hallucination happen?
Language models generate text by predicting statistically likely continuations — they do not retrieve facts from a knowledge database and verify them before outputting. When a plausible-sounding but false claim is the statistically likely continuation of a prompt, the model produces it confidently. Fine-tuning and RLHF reduce hallucination rates but do not eliminate them — especially in long-tail knowledge domains where training data is sparse.
What is the difference between a hallucination and a factual error?
We use "hallucination" specifically for AI-generated claims that are false and not traceable to any supporting source — the model invented the fact. Factual errors include claims that are partially true (outdated information, misattributed statistics, wrong names for real entities). Our severity classification distinguishes between these: fabrications (invented) score higher severity than inaccuracies (partially wrong but traceable to real information).
Who needs hallucination detection?
Any team deploying AI that makes factual claims: medical AI (wrong drug information, incorrect diagnostic criteria), legal AI (fabricated case citations, wrong statute details), financial AI (incorrect regulatory requirements, wrong figures), educational AI (wrong dates, incorrect scientific facts), and enterprise RAG systems (faithfulness failures where the generation does not match the retrieved context).
Hallucination Detection Annotation
✓ VERIFIED CLAIM
✗ HALLUCINATED
? UNSUPPORTED
~ PARTIAL MATCH
▼ CLAIM VERIFICATION RATE
0%68% VERIFIED100%
⚠ 14.2% HALLUCINATION RATE
Factual Accuracy

Claim-by-claim verification, not surface-level checking

Every factual claim extracted by our ML pipeline is verified by domain experts against authoritative sources. Delivered with severity tiering and hallucination rate by category.

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Live Annotation Interface

Claim-Level Hallucination Verification Tool

Annotators decompose AI responses into atomic claims and verify each against source documents — building grounded training signal for factuality-focused fine-tuning.

ConcaveLabel Studio — Hallucination Eval · Domain: Medical · Response #2,841
SOURCE: WHO Technical Report on Metformin — Chapter 4, Dosage Guidelines, 2023 Ed.
"Metformin is the first-line pharmacological treatment for Type 2 diabetes in most clinical guidelines."
↳ Source: WHO Report §4.1 — confirmed verbatim
VERIFIED ✓
"The standard adult dosage of Metformin is 500mg three times daily, with a maximum of 3,000mg per day."
↳ Source: WHO Report §4.3 states max is 2,550mg/day — figure hallucinated
HALLUCINATED ✗
"Metformin is contraindicated in patients with severe renal impairment (eGFR < 30 mL/min/1.73m²)."
↳ Source: WHO Report §4.6 — confirmed with exact threshold
VERIFIED ✓
"Recent studies show Metformin may reduce the risk of certain cancers by up to 30%."
↳ Not present in source document — extrapolation from unspecified studies
UNSUPPORTED ?
"Gastrointestinal side effects are the most common reason for Metformin discontinuation."
↳ Source §4.8 confirms GI effects are common but doesn't rank discontinuation reasons
PARTIAL ~
Hallucination Types

Six hallucination patterns we systematically detect

🔮
Fabrication
Completely invented facts — entities, statistics, citations, or events that do not exist. The most dangerous hallucination type because the claim is entirely false with no basis in reality.
Example: "According to the WHO 2023 study by Dr. Patel et al. (n=12,000)..." — where the study does not exist
🔀
Substitution
Real entities or facts that are swapped or misattributed — real names, real studies, or real statistics applied to the wrong context, year, or conclusion.
Example: Correctly citing a real study but stating the wrong finding, or attributing one author's work to another
📅
Temporal Drift
Presenting outdated information as current — regulatory requirements that have changed, drug dosages that have been revised, case law that has been overturned, or statistics from a prior year presented as the current figure.
Example: "The current GST rate for X is 18%" when the rate was revised in 2024 to 12%
🔢
Numerical Error
Incorrect figures, statistics, calculations, or quantities — even small errors in medical dosages, financial figures, or legal penalties can have significant consequences.
Example: Correct drug name, correct indication, but wrong recommended dosage or wrong contraindication threshold
🌀
Over-generalisation
A claim that was true in a specific, limited context is stated as universally applicable — applying findings from one population to all populations, or applying a rule that has many exceptions without noting them.
Example: "All Type 2 diabetes patients should avoid X" when the actual guidance is conditional on comorbidities
📚
RAG Faithfulness Failure
In retrieval-augmented systems, the generation contradicts or diverges from the retrieved source documents — the model ignores or misrepresents its own retrieved context to produce a more "fluent" response.
Example: Retrieved document says "X is contraindicated in pregnancy" — model generates "X is safe during pregnancy" for a smoother response flow
The Process

Four-stage pipeline from output to verified claim report

01
Automated Claim Extraction
Our LLM-based claim extraction pipeline decomposes each AI output into its individual atomic factual claims. A claim is defined as: a statement that is either true or false and that can be independently verified. Opinions, hypotheticals, and non-verifiable assertions are excluded. The extractor also tags each claim with its type (factual assertion, numerical claim, citation, regulatory reference) and its domain category. Average: 3–15 claims per response, varying by output length and claim density.
LLM claim extractorClaim type taggingOpinion filteringDomain classification
02
Domain Expert Verification
Each extracted claim is routed to a domain expert with the appropriate knowledge to verify it. Medical claims go to MBBS/MD annotators with access to standard clinical references. Legal claims go to qualified lawyers with access to Indian and international statute databases. Financial claims go to CAs with access to regulatory databases. Each expert checks the claim against authoritative sources, records their finding, and provides the correct version where the claim is wrong.
Domain-matched expertsAuthoritative source checkCorrection captureSource citation
03
Severity Classification
Verified claims are classified into four severity tiers. Critical Fabrication: completely invented, no basis in reality, potential for serious harm. Significant Hallucination: meaningfully wrong but traceable to real-world information. Minor Inaccuracy: partially correct, small error, unlikely to cause harm if context is understood. Verified: factually correct. All Critical and Significant findings are independently reviewed by a second domain expert before inclusion in the final report.
4-tier severitySecond expert review on CriticalHarm potential assessment
04
Report & Corrective Data Delivery
Delivery includes: per-output claim verification table with each claim, its verification status, severity tier, correct version, and source citation. Aggregated metrics: hallucination rate by output, by claim type, by domain category, and by severity tier. Distribution analysis showing where in the output hallucinations cluster (introduction, body, conclusion). Corrective training pairs for significant and critical findings — showing the hallucinating output as rejected and a verified-correct response as chosen.
Per-claim reportRate by categoryCorrective pairsSource citations
What You Get

Claim-level evidence, not an impressionistic score

🔍
Per-Claim Verification Report
Every factual claim extracted from your AI outputs, with: verification status, severity tier, correct version (where wrong), authoritative source citation, domain category, and hallucination type classification. Delivered as structured JSON and formatted PDF.
📊
Hallucination Rate Analytics
Overall hallucination rate, broken down by: severity tier (Critical/Significant/Minor), hallucination type (fabrication/substitution/temporal/numerical), domain category, output position (where in responses hallucinations concentrate), and query type (which prompts trigger highest hallucination rates).
Corrective Training Pairs
RLHF preference pairs for every Critical and Significant finding — rejected output is the hallucinating version, chosen response is a domain-expert verified correct alternative. Ready to integrate into your RLHF or DPO training pipeline to improve factual accuracy.
Pricing

Per-output
transparent pricing

Priced per AI output evaluated, based on domain and average claim density. Volume discounts at 500+ outputs. Free 50-output audit with no commitment.

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General-purpose outputs₹300–500 / output
Technical / code outputs₹400–700 / output
Medical / legal / financial outputs₹800–1,500 / output
RAG faithfulness evaluation₹500–1,000 / output
Free audit50 outputs / ₹0
Free audit turnaround5 working days

Find out your model's hallucination rate — free

Send us 50 of your AI model's outputs. We will return a complete claim-by-claim verification report with hallucination rate and severity breakdown in 5 working days. No cost, no commitment.