There are times when you might pause for a moment while using ChatGPT. It clearly sounds plausible, but upon checking later, you find that the facts are nonexistent or the dates, people, or sources are incorrect. Consequently, many people wonder, "Why is it so confidently wrong?" The reason ChatGPT makes up facts is that it is not a human-like entity that verifies facts before speaking, but rather a language model that generates the most plausible sentences based on patterns found in its learned data. OpenAI also notes that ChatGPT can sometimes produce answers that differ from the facts, and they commonly describe this phenomenon as "hallucination.".
Direct Answer
There are three main reasons why I am stating that ChatGPT does not exist.
This is because it generates the most natural sentence probabilistically, rather than a method of “retrieving by remembering” facts.
• There is a structure that makes it easier to be rewarded for making an estimation rather than remaining silent when hearing something unknown, so you may be inclined to give a plausible answer rather than saying “I don’t know.”.
• The likelihood of errors increases with the latest information, ambiguous questions, rare topics, and content requiring source verification. OpenAI also advises that the latest information may not be reflected unless tools are used.
Key Summary
• ChatGPT is a language generator, not a search bar.
Plausibility and factuality are different. Just because a sentence sounds natural does not mean the content is correct.
• Dates, statistics, paper titles, legal matters, recent news, and citations are particularly prone to errors. OpenAI states that incorrect definitions, dates, facts, and non-existent citations and sources may occur.
• Important information must be verified through the official website, original sources, and actual links.
FAQ
Does ChatGPT lie on purpose?
No. Usually, it is not an intentional attempt to deceive, but rather an error that occurs while generating a sentence that appears likely to be correct. OpenAI explains this as a phenomenon where answers are generated that are plausible but differ from the facts.
Why don't you say you don't know if you don't?
OpenAI explains that current evaluation and learning methods can operate in a way that favors “getting the correct answer,” meaning that estimating can be more scoring-wise advantageous than leaving blanks. Consequently, the model attempts an answer even when it is uncertain.
Can even the latest information be wrong?
That is correct. OpenAI help advises that the model has knowledge point-in-time limitations, and that subsequent events may not be reflected if the tool is not used.
Are there cases where even the source is fabricated?
Yes, it exists. OpenAI clearly states that it can invent non-existent citations, research, and references.
Then is it a tool that cannot be trusted at all?
It is not to that extent. It is very useful for drafting, organizing explanations, expanding ideas, and refining sentences. However, critical factual judgments must be accompanied by verification. NIST also treats generative AI as a technology requiring separate risk management.
You must first understand why ChatGPT states facts that do not exist.
Many people get stuck here. Because the answer is so natural, they tend to move on, thinking, "This must be correct." However, ChatGPT is not a system that directly observes and verifies the world like a human. OpenAI advises that while ChatGPT is designed to generate useful answers based on patterns in training data, it can produce incorrect or misleading outputs.
There is one important point here. ChatGPT is not a “machine that retrieves answers from a database,” but a “sentence-generating model.” Therefore, if the question is ambiguous, covers an area of vague memory, or the original data itself is complex, it attempts to fill in the gaps with plausible sentences. OpenAI’s SimpleQA paper also points out that factual accuracy remains a major challenge, and that even current top-tier models can generate false or unfounded answers.
Explanation of Generative AI Concepts
Generative AI refers to AI that generates new outputs, such as text, images, and voice. NIST describes Generative AI as a family of AI that creates derived synthetic content by mimicking the structure and characteristics of input data.
ChatGPT is a large-scale language model that is particularly strong in text generation. When a user inputs a question, it constructs an answer by concatenating words that are likely to follow. While this process is highly sophisticated, it differs from a structure that determines whether something is "true or false" on its own, like a human does. Therefore, even if the text is smooth and persuasive, parts of the content may differ from reality.
How Generative AI Works
Isn't this part quite confusing? Many people think that ChatGPT is as if it has a massive encyclopedia placed entirely inside their heads. However, in reality, it is closer to a method that calculates the most natural next expression based on the question. OpenAI also explains the hallucination phenomenon in language models, stating that rather than the model intentionally lying, it is structured to produce estimations under statistical pressure.
In particular, OpenAI explains that current evaluation methods may favor "models that attempt an answer" over "models that stop when they don't know." For example, if a model says "I don't know" when it doesn't know a birthday, it always receives a score of 0, whereas estimating any date creates a probability of being correct, even if very low. If this structure is repeated, the model is more likely to develop a habit of estimating rather than cautiously leaving things blank.
Therefore, errors in ChatGPT are not merely simple mistakes. They are phenomena resulting from the intertwining of learning methods, evaluation methods, question structures, and the use of tools. NIST also believes that generative AI requires separate management because it can increase risks in ways different from general software.
Typical situations where ChatGPT states facts that do not exist
1. When the question is too broad or ambiguous
If the question is vague, the answer will be shaky as well. For questions lacking criteria, such as “What is the best AI these days?”, there is a greater likelihood of a plausible explanation based on context rather than an accurate comparison. OpenAI also advises that overly confident answers may emerge in response to complex or ambiguous questions.
2. When you need the latest information but do not use the tool
Time is critical for information such as news announced today, changed laws, the latest prices, and current job titles. OpenAI Help explains that models may not inherently know information from a point in time since training, and in such cases, tools like search are necessary.
3. When dealing with rare names, papers, statistics, and proper nouns
In such content, changing even a single character results in completely different information. OpenAI has stated that it can generate not only incorrect definitions, dates, and facts, but also non-existent sources or citations. In fact, it is dangerous to use paper titles, court precedents, article headlines, or interview statements without verification.
4. When the answer format is too complete
Ironically, the smoother a sentence is, the more trustworthy it becomes. However, natural sentences and accurate facts are different matters. Both OpenAI's research and documentation emphasize that even if ChatGPT appears confident, it may be separate from its reliability.
Key Features of Generative AI
If you use ChatGPT yourself, there are characteristics you will immediately notice. Its ability to make text flow smoothly, compress long content, and anticipate the intent of questions to some extent to connect with the content is truly strong. However, precisely because of these characteristics, it also exhibits a tendency to smoothly fill in any blanks.
The representative characteristic is this kind of thing.
• Continue writing naturally following the context.
You can also fill in unknown information in the form of sentences.
It may look better in terms of the completeness of the answer rather than fact-checking.
Accuracy can be improved by adding tools such as search and data analysis.
If you use it without knowing this feature, you will come to accept “fluent answer = correct answer.” However, the important thing is that ChatGPT is good at generating probabilistically natural answers, but it is not an engine that always states only verified facts.
Real-world use cases of Generative AI
However, there is no need to be too intimidated. When used effectively, generative AI can significantly boost productivity. It is exceptionally strong at tasks such as drafting, structuring text, explaining complex concepts, organizing interview questions, explaining tables, and drafting emails. This is because, in these tasks, "expression and structure" are often more important than "absolute facts.".
Conversely, there are also cases where copying and using it directly is dangerous.
• Information with high error costs, such as medicine, law, and tax
• Sensitive information at this point in time, such as the latest news, stock prices, policies, and regulations
• Paper citations, case numbers, statistical figures, interview remarks
• Sentences in company reports or proposals that require a source
Using this method will definitely make a difference. For parts where facts are important, it is a good habit to first receive “answers with sources” or “a list of claims requiring verification” from ChatGPT, rather than just receiving “answers” alone. OpenAI also recommends verifying information with reliable sources.
How to Use Generative AI for Beginners
If you are a first-time user, it is safer to think of ChatGPT as a drafting partner rather than a machine that provides correct answers. Its strengths come into play when you make requests such as, “Simplify this sentence,” “Summarize the key points,” or “Give me a checklist of points to verify.”.
The way you ask questions is also important. It is much better to narrow the scope, such as asking, “Based on 2026, only the application conditions, and mark separately any items that require official verification,” rather than simply saying, “Tell me about the Youth Monthly Rent Subsidy.” As ambiguity decreases, the room for the model to fill in the blanks based on imagination also diminishes.
Make sure to develop a verification habit.
• Check the original text for dates, amounts, and details.
• Open actual article or paper for citation
• Reconfirm the name of the institution, statute, and case number on the official website.
• Check web searches or official announcements for the latest information.
Even doing just this much significantly reduces errors. NIST also believes that generative AI requires an approach to identify and manage risks before and after use.
Advantages and Disadvantages of Generative AI
To start with the advantages, generative AI is a great help when you feel lost at the beginning. It excels at shortening long texts, rewriting explanations to suit beginners, and branching out ideas. It also speeds up your work.
However, there are also clear downsides. It can present incorrect information as if it were true and make sentences without sources appear as if they were. The OpenAI help documentation explicitly states that incorrect facts, dates, definitions, and non-existent research or references may appear.
Therefore, the key is not "whether to trust it or not." It is distinguishing "how much to entrust and where to leave it to human verification." If you draw this line well, ChatGPT becomes a quite useful tool. Conversely, without this line, a small error can escalate into a major misunderstanding.
Frequently Asked Questions (FAQ)
Are all posts created by ChatGPT dangerous?
That is not the case. It is very helpful for drafting explanations, organizing structures, and improving sentences. However, it is much safer to select and verify only the sentences that require fact-checking.
Why do you look confident when answering?
Language models are optimized to generate natural-sounding sentences, so their expressions may appear assertive. OpenAI also advises that confidence and reliability are not the same thing.
Will adding a search function completely solve the problem?
Not entirely. However, it is very helpful for verifying the latest information and sources. OpenAI also explains that tools such as search, data analysis, and deep research can actually help improve accuracy.
Which questions are particularly dangerous?
Questions where accuracy is critical, such as the latest news, law, medicine, investment, statistics, citations, and paper titles, are more dangerous. For such content, you must double-check the original source.
If you understand why ChatGPT states facts that aren't true, your usage changes.
If you understand why ChatGPT makes mistakes, you can view this tool with less fear. The issue is less that “AI lies” and more that it “can generate plausible sentences without fact-checking.” OpenAI describes this as a hallucination and states that incorrect answers or unfounded sources may appear.
Therefore, the user's attitude is also important. You need to develop the habit of narrowing down your questions, using tools for the latest information, and double-checking important figures and sources. These small differences can completely change the results. You just need to remember that ChatGPT is not a magic validater, but a powerful aid when used properly.