What it doesn't mean
It's a metaphor. The system isn't perceiving anything. It produces text that is plausible but false. Such errors are also called confabulations, and the word is often cited as an example of how readily we describe machines in human terms.
Cambridge's publishing manager pointed out that large language models can only be as reliable as their training data, and that people still need to apply their own critical thinking to what the tools produce.
What it really means
In 2023 two dictionaries, working separately, picked the same word for the year: hallucinate.
Cambridge Dictionary announced it first, on 15 November. It added a new definition: when an artificial intelligence hallucinates, it produces false information. It linked the choice to a year-long surge of interest in generative AI tools like ChatGPT, and to public attention shifting towards what these tools can't do. Cambridge's publishing manager, Wendalyn Nichols, said the fact that AIs can hallucinate reminds us that humans still need to bring critical thinking to them.
Dictionary.com followed on 12 December. It had added the AI sense that year and set out its reasons with data. Lookups of hallucinate were up 46% on the year before, and use in digital media was up 85%. Lookups of AI-related words in general were up 62% on average. It called hallucinate the word that best captured AI's effects on language and life. It also pointed out that hallucinate is unusual among AI words because it names a way the technology fails, not how it works. That puts it alongside cautionary tech words such as spam and virus.
The examples were already piling up. Reporting on Cambridge's pick mentioned a US law firm that cited invented court cases after using ChatGPT for research, and a factual slip about the James Webb Space Telescope in a promotional video for Google's Bard.
The word is older than the problem. Hallucinate came into English in the 1650s from Latin alucinari, "to wander in the mind". Dictionary.com traces its computing use to a 1971 paper on getting computers to read handwriting. The metaphor says something about us as well. An AI ethicist at Cambridge University, quoted in the coverage, pointed to how readily we describe machines in human terms. The word has stuck all the same, and it is a useful reminder to check what the machine says.
Where it comes from
from Latin alucinari, 'to wander in the mind, dream, ramble'
Recorded in English from the 1650s meaning 'to have illusions'. The Latin may come from a Greek word meaning 'to wander in mind, be distraught'. The AI sense is a metaphorical extension, a new figurative use growing out of the literal one.
- 1650s
Hallucinate enters English, meaning to have illusions.
- 1971
One of the first documented computing uses, as the noun 'hallucination', appears in a research paper on getting computers to read handwriting.
- 1990s
The term, including the verb, begins to appear in machine-learning and AI writing.
- 2023
After ChatGPT's launch in late 2022, public attention turns to AI's confident mistakes. Dictionary.com adds the AI sense this year.
- November–December 2023
Cambridge Dictionary (15 November) and Dictionary.com (12 December) both name hallucinate Word of the Year 2023.
In real life
- I asked the chatbot for three sources on medieval bread prices, and it hallucinated two of them, authors, titles and page numbers included.
- The summary looked perfect until we noticed it had hallucinated a quote from the chief executive that she never said.
- In the older sense: after three days without sleep, the climbers began to hallucinate voices in the wind.
Questions
Q01What does it mean when AI hallucinates?
It means the AI has produced false information and presented it as true, such as invented facts, quotes or references. Cambridge Dictionary's definition is that when an artificial intelligence hallucinates, it produces false information.
Q02Why was hallucinate the 2023 Word of the Year?
Cambridge Dictionary chose it after a year-long surge of interest in generative AI tools like ChatGPT. Dictionary.com chose it too, reporting a 46% rise in lookups and an 85% rise in use in digital media, and saying it best captured AI's effects on language and life.
Q03Can AI hallucinations cause real harm?
Yes. Coverage of Cambridge's announcement mentioned a US law firm that cited invented court cases after using ChatGPT for research, and a factual error about the James Webb Space Telescope in a promotional video for Google's Bard chatbot.
Q04Where does the word hallucinate come from?
From Latin alucinari, 'to wander in the mind' or 'to dream'. It has been in English since the 1650s. Computer scientists borrowed it: a 1971 paper on reading handwriting is one of the first documented uses.
Sources
- Dictionary.com's 2023 Word of the Year Is… hallucinate (12 December 2023).
- Cambridge Dictionary reveals word of the year for 2023. The Independent (15 November 2023).
- Cambridge Dictionary Word of the Year 2023: hallucinate.
- Hallucination (artificial intelligence): Wikipedia.
- hallucinate (v.): Online Etymology Dictionary.