Why it happens: the model produces likely-sounding text, and a plausible fake can be ‘likely’.
Warning signs: very specific numbers without sources, references you cannot find, and answers that change when you ask again.
Check routine: (1) Is it important? (2) Find the claim in a reliable source such as an official site, reputable news or a textbook. (3) Check any references actually exist. (4) Ask the AI for its uncertainty. (5) If it matters — health, money, law — ask a qualified person.
Some tools can search the web and show links; still open the links and read them.
Worked example 1
A chatbot says ‘According to a 2019 Oxford study, 83% of cats prefer jazz.’ What do you do?
Very specific statistic plus a vague source — warning signs.
Search for the study on Oxford's site or a research database.
If you cannot find it, treat it as invented.
Answer: Do not use it unless you can find the actual study.
Try it online · print it · check it
Practice questions
Intermediate · ages 11+
AI errors and hallucinations
NameDate
Answer each scenario: trust, check or ask an expert.
1.An AI suggests a synonym for ‘happy’ in a birthday card.
2.An AI gives a quote from a famous person for your essay.
3.An AI tells you how much of a medicine to give a child.
4.An AI lists three books as sources for your report.
5.An AI says what your tenancy law rights are for a dispute.
Intermediate · answersAnswer key
AI errors and hallucinations — answer key
Answer each scenario: trust, check or ask an expert.
1.An AI suggests a synonym for ‘happy’ in a birthday card.trust
2.An AI gives a quote from a famous person for your essay.check
3.An AI tells you how much of a medicine to give a child.ask an expert
4.An AI lists three books as sources for your report.check
5.An AI says what your tenancy law rights are for a dispute.ask an expert
Tips
Common mistakes
Checking only by asking the same AI ‘are you sure?’.
Trusting a confident tone. AI tools sound equally sure when they are wrong.
