liveBook · Manning

Hallucination

As explained in Effective Data Analysis

A hallucination is generated model output that is nonsensical, fabricated, or factually inaccurate despite being presented as a response.

A hallucination is generated output that is nonsensical, fabricated, or factually inaccurate even when it appears to answer the prompt. Generative AI models can produce hallucinations because they predict likely output, and that prediction can be wrong. section 12.4.1

Hallucinations create practical risks in analytics workflows:

  • Treat current events and recently released information cautiously because model training data may not be up to date. section 12.4.1
  • Check generated code against the versions of the Python packages actually installed; newer package assumptions can create troubleshooting work. section 12.4.1
  • Use generative AI to reduce repetitive work while recognizing that its outputs remain subject to substantive limitations. section 12.4.1

A misleadingly confident response

A model may generate an answer about 2024 world events despite having no sufficiently recent training information, or produce code written for a later Python package version. Both outputs can sound useful while being inaccurate or unusable. section 12.4.1

Figure 12.10 Generative AI creates new content based on user-submitted prompts.
figure

Shows the prompt-to-content relationship that underlies generative output and its potential for error. section 12.4.1

How Effective Data Analysis covers it

How deep it goes
Defines the failure mode and links it to prediction errors, but does not develop detection or mitigation procedures.
Examples
Uses stale answers about current events and incompatible Python package code as concrete failure examples.
What you can do after
Evaluate generated answers as potentially inaccurate and account for freshness and package-version limitations in analytics work.
How it connects
Connects hallucinations with generative AI, large language models, foundation models, prompts, and data analytics.

Also explained in

Compare how 29 books explain hallucination →

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Effective Data Analysis. The section links point to the parts of the book it draws on.