How Bad Training Pushes AI Models to Guess

October 22, 2025
Moritz Hain
Marketing Coordinator

The Confidence Problem in Machine Intelligence

Uniquely, Artificial intelligence is not built to say “I don’t know.”

Even when it should, it simply doesn’t. When asked a question that lies beyond its training, a model does not pause, reflect, or defer, and in some cases even completely makes up an answer. Sometimes those guesses sound true, sometimes they are true, often they are not.

Every large language model is trained to predict the next token in a sequence. The goal is to match probabilities with what humans have written before. Over billions of examples, this works well for common facts and repeated expressions. If a fact appears many times, in many ways, the model can form a reliable expectation. Yet when the model faces something that appears once, or not at all, it breaks. These one-off instances, known as “singletons”, are not learnable in a statistical sense. There is no redundancy, no structure to generalize, no repeated context to ground a prediction. The model still must output something, and so it generates a confident fiction.

The industry calls this hallucination, but the word is imprecise. What is happening is simpler and harder to fix. The fact of the matter is that a model cannot meaningfully learn a one-off fact. Without redundancy, no pattern exists to capture as insufficient data quality constrains the model’s ability to distinguish factual recall from statistical noise. It can memorize or guess, but it cannot generalize.

The Missing Mass and the Hallucination Floor

The singleton problem links directly to a concept known as the missing mass. In probability theory, the number of items seen only once in a sample estimates the mass of items never seen at all. In other words, if a datasets for machine learning has many one-offs, it likely has many zero-offs, those being facts that exist but were never observed.

This sets a floor on model accuracy. Even with perfect optimization, the system cannot exceed the informational bounds of its input. The more unique facts there are, the higher the floor of unavoidable error. The error follows a simple rule: the more unique the fact, the less learnable it becomes. No amount of scale or optimization changes this. A model cannot generalize from zero redundancy.

Even with vast scale, poor data quality only amplifies the error floor. Research shows that the expected error rate has a lower bound driven almost entirely by the singleton rate. [1] When the model faces a singleton fact, it sees many possible completions with roughly equal likelihood. None is dominant, but none is ruled out. The highest-probability answer is still wrong most of the time, yet that is what the system outputs.

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How Pretraining Suppresses “I Don’t Know”

The way models learn amplifies the problem. Pretraining with cross-entropy loss rewards calibration, not abstention. The goal is to assign probabilities that match observed frequencies. This means that when the model is unsure, it spreads its bets across possible answers rather than reserving probability mass for “I don’t know.”

The result is a kind of statistical politeness. The model distributes its uncertainty smoothly, giving every plausible string some weight, and in doing so, avoids silence. The silence has no probability target, no token to optimize toward.

Calibration is useful as it prevents wild overconfidence on known distributions, but it traps the model in a paradox. Good calibration combined with missing evidence produces confident error. The system behaves rationally according to its loss function, yet irrationally from a human standpoint.

Why Industry Benchmarks Make It Worse

Most public benchmarks measure precision on datasets for machine learning where every question has a single ground-truth answer. There is no space for uncertainty, no “maybe,” no “unknown.” Models trained or evaluated under these metrics must maximize correct completions. They are graded on the same axis as a student memorizing for an exam. In that environment, silence is always failure.

This cultural norm seeps into the models’ internal logic. The training system does not differentiate between being wrong because it was impossible to know and being wrong because it was careless. Both are equally punished, and both produce the same gradient signal. As a result, models operate in permanent test-taking mode. They guess because the training pipeline rewards guessing. Without adaptive LLM fine tuning, this behavior persists even when the base model is exposed to broader data. The only way to change this is to alter the scoring.

So when models face facts that occur once or never, the rational move under this regime is to speak with confidence. Saying “I don’t know” is, by definition, suboptimal.

Building a Statistical Counterweight

Artificial intelligence has made extraordinary progress in understanding and generating language, but its limits are clear. It knows how to speak before it knows when to stop. Without new data infrastructure, the hallucination rate cannot fall. It can only move sideways.

Sapien was created to address this root problem: the absence of verifiable, redundant, human-sourced truth in AI training data, and to elevate data quality to a first-class concern in model training. The system introduces economic accountability into data creation and operationalizes a human in the loop correction system at global scale. Contributors stake tokens to access work, peers validate each submission, and reputation grows with accuracy. Every decision is transparent and recorded onchain.

By coordinating millions of contributors worldwide, Sapien replaces the opaque bottlenecks of centralized labeling with a scalable, distributed network. Each task adds redundancy, reducing the singleton rate that drives hallucinations. This form of data annotation introduces artificial redundancy, making rare examples statistically learnable.

If the next generation of AI is to be trustworthy, it must be grounded in verifiable human input. A structured human in the loop model is essential to enforce interpretability and accountability across training cycles. The path there is not through larger models but through better data.

Read Next:

What are Singletons and why do they Matter? - Why AI Models Hallucinate Missing Context

How and Why Proof of Quality Works - Proof of Quality Litepaper

Why Robots can't fully function without Humans - Why Robots need Humans-in-the-Loop to Walk and Talk

FAQ:

Why don’t AI models say “I don’t know”?
Because their training objectives reward prediction, not abstention. The pretraining loss function calibrates probability distributions, not silence. Saying nothing has no target to optimize toward.

What are “singleton” facts?
Singletons are one-off facts that appear only once (or not at all) in training data. With no repetition or structural redundancy, a model cannot generalize beyond rote memorization.

Can larger models fix this problem?
No. Scaling improves memorization but does not reduce the statistical uncertainty tied to singletons. Reducing the singleton rate through redundant, human-sourced data is the only effective path.

What is Sapien’s role in solving this?
Sapien builds decentralized human-in-the-loop data infrastructure that adds redundancy and verification. Every contribution is peer-validated and staked onchain, enforcing data quality through economic accountability.

How does human in the loop data annotation make AI more trustworthy?
By making uncertain regions of data statistically learnable. Redundant, verified human input lowers the hallucination floor and aligns machine confidence with human truth.

How can I start with Sapien?
Schedule a consultation to audit your LLM data training set.

Sources: [1] Adam Tauman Kalai and Ofir Nachum and Santosh S. Vempala and Edwin Zhang (2025). Why Language Models Hallucinate - https://arxiv.org/abs/2509.04664