What is LLM Hallucination?

AIF-C01 By islever Editorial Last updated Aug 19, 2026

Short answer

B Hallucination

Question

An AI practitioner is using a large language model (LLM) to create content for marketing campaigns. The generated content sounds plausible and factual but is incorrect. Which problem is the LLM having?

Data leakage
Hallucination Correct Answer
Overfitting
Underfitting

Key Takeaways

The question tests the definition of hallucination, with the trap being confusion between factual errors and data privacy issues.

LLM hallucination occurs when models generate plausible but factually incorrect content. The community consensus confirms that this is a primary risk in generative AI applications like marketing.

Common mistake: Data leakage is often chosen incorrectly because it sounds like a serious security issue, but it involves exposing private data, not generating false facts.

Expert Analysis

Why the Answer Is Correct

Hallucination is defined as the generation of text that is coherent and plausible but factually incorrect or nonsensical. This happens because LLMs predict next tokens based on patterns rather than retrieving verified facts from a knowledge base.

Why the Other Options Are Wrong

Data leakage involves exposing sensitive training data, which is a privacy issue, not a factual accuracy one. Overfitting and underfitting are model training states related to performance on unseen data, not specific outputs containing false information.

Community Comment Notes

Comments consistently identify hallucination as the correct term for 'plausible but incorrect' outputs. Users emphasize that this is a known limitation of generative models relying on pattern matching rather than truth grounding.

Exam Strategy

Distinguish between output quality issues (hallucination) and security issues (data leakage). Remember that hallucinations sound real but are made up, whereas overfitting/underfitting relate to training metrics.

Community Votes

100%

100% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

AzureDP900 👍 2 Answered B

Hallucination is a phenomenon in which an LLM generates text that sounds plausible and factual but is actually incorrect or nonsensical. This occurs when the model is overconfident in its ability to generate coherent text based on patterns it has learned from training data.
L1234567890 👍 2

B. Hallucination is the right answer
Jessiii 👍 1 Answered B

B. Hallucination: In the context of large language models (LLMs), hallucination refers to when the model generates content that sounds plausible and coherent but is factually incorrect or misleading. This is a common issue with generative models, where they may produce text that seems accurate on the surface but is not grounded in real data or facts.
L1234567890 👍 2 Answered B

Hallucination

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