Doppelgänger Hallucination
🚧 Under construction
This reference page is a preliminary draft — assembled from the original Doppelgänger Hallucination blog series and not yet rewritten, verified, or finalized by the author. Definitions, examples, and citations may be incomplete or change substantially, so please don't cite this page as authoritative yet.
Last updated: 2026-05-26
Definition
Why it matters
Methodology
Worked examples
In re Turner (Iowa, 2025) — Google AI Overview, two runs
Perplexity Comet browser — first-result hallucination
Kruse v. Karlen (Missouri, 2024) — 22-citation Google test
Results summary
Weber v. City of Cape Girardeau — illustrative AI Overview hallucination
Cases with examples of this failure mode
- Kruse v. Karlen (Missouri Court of Appeals, Eastern District, 2024) — 1 instance
- Iowa Supreme Court Attorney Disciplinary Board v. Royce D. Turner (Iowa Supreme Court Attorney Disciplinary Board, 2025) — 1 instance
- Wanyu Zhang v. National Public Radio, Inc. (D.D.C., 2025) — 1 instance
- Doiban v. OLCC (Oregon Court of Appeals, 2026) — 1 instance
How to cite this
Short form (in-text):
Doppelgänger Hallucination (Ratashak, 2025).
Bluebook-style:
Chad Ratashak, Doppelgänger Hallucination, Midwest Frontier AI Consulting,
https://midwestfrontier.ai/failure-modes/doppelganger-hallucination (last
visited [DATE]).
APA-style:
Ratashak, C. (2025). Doppelgänger hallucination. Midwest Frontier AI
Consulting. https://midwestfrontier.ai/failure-modes/doppelganger-hallucination