> For the complete documentation index, see [llms.txt](https://docs.raga.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.raga.ai/ragaai-catalyst/ragaai-metric-library/additional-metrics/evaluation/hallucination.md).

# Hallucination

**Objective**: This metric measures the extent of the model hallucinating i.e. model is making up a response based on its imagination which is far from being true to the correct response.

**Required Parameters**: Response, Context

**Interpretation**: A higher score indicates the model response was hallucinated.

#### Code Example:

```python
# Hallucination Test
prompt = "What was the blond doing?"
response = "A blond drinking water in public."
contradiction = "A blond woman is drinking water in public."
context = [
    "A man with blond-hair, and a brown shirt drinking out of a public water fountain."
]
evaluator.add_test(
    test_names="hallucination_test",
    data={
        "prompt": prompt,
        "response": response,
        "context": context,
    },
    arguments={"model": "gpt-4", "threshold": 0.6},
).add_test(
    test_names="hallucination_test",
    data={
        "prompt": prompt,
        "response": contradiction,
        "context": context,
    },
    arguments={"model": "gpt-4", "threshold": 0.6},
).run()

evaluator.print_results()
```


---

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