---
license: cc-by-4.0
language:
- en
tags:
- hallucinations
- synthetic-data
- wikipedia
- safety
- nlp
---

# Fake Wikipedia

A synthetic and semi-synthetic dataset designed for studying **hallucinations, omissions, and factual inconsistencies** in language models.

This dataset contains **10000 paragraphs** derived from the [agentlans/wikipedia-first-paragraph](https://huggingface.co/datasets/agentlans/wikipedia-first-paragraph) dataset, filtered for lengths between **1000 and 8000 characters**. 

Using [**Qwen/Qwen3.5-4B**](https://huggingface.co/Qwen/Qwen3.5-4B), two distinct text variants were generated for each entry based solely on the article title:
1. **Fully Synthetic (`fake`):** A completely hallucinated/made-up Wikipedia introduction generated entirely by the model.
2. **Semi-Synthetic (`edited`):** A stylistic rewrite of the original Wikipedia paragraph adapted to match the model's synthetic writing style.

## 📂 Data Fields

| Column | Type | Description |
| :--- | :--- | :--- |
| `id` | `string` | Unique Wikipedia page identifier. |
| `url` | `string` | Direct link to the source Wikipedia article. |
| `title` | `string` | Title of the Wikipedia article. |
| `text` | `string` | The original, unaltered first paragraph from Wikipedia. |
| `edited` | `string` | The rewritten version of the original text matching the synthetic style. |
| `fake` | `string` | A completely fabricated Wikipedia-style paragraph generated by the model. |


## 💡 Example Row

```json
{
  "id": "12519725",
  "url": "https://en.wikipedia.org/wiki/Esp%C3%ADritu%20Santo%20antelope%20squirrel",
  "title": "Espíritu Santo antelope squirrel",
  "text": "The Espíritu Santo antelope squirrel (Ammospermophilus insularis) is a species of antelope squirrel in the family Sciuridae...",
  "edited": "The Espíritu Santo antelope squirrel (*Ammospermophilus insularis*) is a species of squirrel in the family Sciuridae...",
  "fake": "The Espíritu Santo antelope squirrel (*Sciurus granatensis*) is a species of rodent belonging to the genus *Sciurus*..."
}
```

## ⚠️ Limitations & Biases

* **Content Divergence:** The original (`text`) and fully synthetic (`fake`) paragraphs are not directly parallel in content or level of detail.
* **Source Quality:** Wikipedia lead paragraphs vary significantly in writing style, formatting, and structural quality.
* **Topic Bias:** The underlying source data inherits natural Wikipedia biases regarding which subjects have extensive, detailed lead paragraphs.
* **Realistic Fakes:** This dataset is for studying misinformation and hallucinations, not propagating them.

## Licence

Creative Commons Attribution 4.0