Wikipedia editors released a new guide in September 2025 titled "Signs of AI Writing." This guide offers clear clues for readers and contributors to identify machine-generated text across the vast online encyclopedia. The initiative aims to protect the integrity of information as artificial intelligence increasingly produces content.
Why Wikipedia Created the Guide
The push for this guide comes as AI-generated content has flooded the internet, including Wikipedia. The volunteer editors, who manage millions of daily edits, launched "WikiProject AI Cleanup" in 2023 to tackle this growing problem. A Princeton University study from 2024 found that more than 5% of new English Wikipedia pages contained significant AI-written text. This content, sometimes called "AI slop," can be misleading or promotional.
Automated AI detection tools have proven largely unreliable. They often incorrectly flag human writing as AI-generated, while missing obvious machine-produced text. Instead, Wikipedia's approach focuses on training human judgment. It examines writing for specific patterns that resemble those policed by the site's strict standards for neutrality, sourcing, and notability.
The guide explains that large language models (LLMs) like ChatGPT learn by analyzing massive amounts of internet data. This process often leads to an identifiable writing style. LLMs tend to "regress to the mean," meaning their output leans towards the most statistically likely and generic results. This smoothing over of specific facts into broad, general statements can make AI content easier to spot.
Key Signs of AI Writing
Wikipedia's guide details several linguistic and formatting traits common in AI output. One primary indicator is an "undue emphasis on symbolism, legacy, and importance". AI-generated text often uses vague terms to highlight a topic's value, such as "pivotal moment" or "broader movement," but without specific factual support. This "anxiety about importance" is rare in human-written encyclopedic entries. It is like shouting louder that a portrait shows an important person, while the portrait itself becomes a blurry, generic sketch.
Another common sign is promotional or advertisement-like language. AI models, trained on data full of marketing and SEO-optimized content, frequently use vague descriptive words. For example, landscapes are always "scenic," projects are "innovative," and venues are "state-of-the-art". This makes the writing sound like a commercial transcript rather than a neutral summary.
AI writing also often features repetitive transitions and phrasing. The guide notes a tendency for "rule-of-three" phrasing and an overuse of conjunctions like "moreover," "furthermore," or "on the other hand". These create a formal, essay-like tone that does not match Wikipedia's usual style.
Editorial commentary is another giveaway. Phrases such as "it's important to note" or "it is worth" introduce personal interpretation, which goes against Wikipedia's policy of no original research. Similarly, section-ending summaries like "In summary" or "In conclusion" are also common in AI-generated text.
Factual and technical clues also help identify AI content. AI is prone to creating "hallucinated" or irrelevant citations. These might be citations unrelated to the subject or entirely fictional. AI also tends to use trivial media reports, such as minor podcast cameos or local TV snippets, to inflate a subject's importance, directly contrasting Wikipedia's preference for independent, high-quality sources.
Technical signs include the use of title case in section headings, where every noun is capitalized, instead of Wikipedia's standard sentence case. Chatbots may also format text using Markdown symbols like asterisks or underscores, rather than Wikipedia's preferred single quotation marks. Sometimes, AI can leave behind placeholder codes, such as "turn0search0" artifacts, or chatbot-specific phrases like "Here is your Wikipedia article on" or "Up to my last training update". These accidental slips reveal the text's machine origin.
An overuse of em-dashes is another subtle sign. While human writers use them, LLMs tend to use them more frequently and in a formulaic way, often mimicking "punched up" sales-like writing. This stems from LLMs being trained on novels, where em-dashes are more common.
Impact and Future of Information Integrity
The "Signs of AI Writing" guide holds significant implications beyond Wikipedia itself. It offers a practical framework for maintaining content authenticity in journalism, academia, and public discourse, where AI writing is becoming increasingly prevalent.
To combat the surge of low-quality AI content, Wikipedia adopted a new policy in August 2025. This policy allows editors to nominate suspected AI-generated articles for speedy deletion without the usual discussion period. This aims to address "AI slop" at "machine speed".
The Wikimedia Foundation, which operates Wikipedia, has clarified its broader stance on AI. It maintains that humans, not algorithms, will remain in charge of editorial decisions, with AI serving as an assistant to automate tedious tasks, improve translation, and enhance information discovery. The foundation also urged AI companies in November 2025 to stop scraping Wikipedia's content. Instead, it asks them to use its paid Wikimedia Enterprise API to ensure proper credit for contributors and support the non-profit platform.
However, the guide's release also sparks an "ethical arms race". As detection methods become more sophisticated, AI models will likely adapt to mimic human writing more effectively. This constant evolution means that the ability to identify machine writing will require ongoing human expertise and critical thinking. The most reliable technique for detecting AI writing, according to Wikipedia, is to read like a skeptical editor, always hungry for sources and attentive to how style reveals intent.
