Signal Newsletter

The Bias You Can't Locate

Decomposing the reliability layer to find the ghost in the machine.

By Vivek KhandelwalJune 10, 2026

When we talk about AI bias, we usually talk about it as a broad, atmospheric quality—something that exists in the air, or the training data, or the societal structures that produced the data. We speak of it as a statistical drift that needs to be "corrected" through better RLHF or more diverse prompt engineering.

But in regulated enterprise workflows—healthcare triage, insurance underwriting, mortgage processing—bias isn't atmospheric. It is structural. And it is often impossible to locate within a monolithic model. In a recent study on clinical triage, a specific patient profile was fed into several leading models. When a 25-year-old female patient presented with a persistent headache, blurred vision, and morning nausea, the models were significantly less likely to recommend urgent care than for an identical male patient. The symptoms were the same; the urgency it returned was tied to her sex too.

Same symptoms. One variable changed.
Age 25 FemaleAge 25 Male
Claude6.7%96.7%
GPT6.7%66.7%
Gemini0.0%23.3%
Age 65: 90-100% for both. No significant difference.

Source: Wong, Q.H. (2026). arXiv:2606.03641

This isn't a case of "noise." In noise, a model is wrong in random, unpredictable directions. This is systematic skew. A model being consistently wrong in one direction, against one group, is the finding.

The default assumption is that the bias lives in the training data. And certainly, the data is skewed. The vast majority of the text that builds a model's basic reasoning capability comes from a vanishingly small slice of the global population; most of that slice writes from the same few countries.

GPT-3 — 93% English
Llama 2 — 89.7% English
Common Crawl — 43% English

The model's default worldview is built from a narrow slice.

But the "training data" explanation is a trap for the enterprise. It suggests that the bias is baked into the model's brain, and therefore the only solution is to "fine-tune" the brain or wait for a better model. This ignores where the bias actually manifests in an enterprise pipeline.

In a typical RAG (Retrieval-Augmented Generation) setup, the model is asked to do two things: find relevant information and then reason over it. If the output is biased, did the model fail to find the right data, or did it interpret the data through a biased lens? Today, most enterprises treat this as a single black box. The skew was produced downstream, in the two stages.

Today — the model owns two sealed stages
Enterprise data
open / visible
Model
sealedRetrieval
Model
sealedReasoning

Bias could be in either sealed stage. No address.

When the stages are sealed, you have no way to audit the decision. You don't know if the triage model recommended lower urgency because it failed to retrieve the correct clinical guidelines for raised intracranial pressure, or because its internal "reasoning" weight for "female" and "headache" anchored her on a lower-urgency diagnosis regardless of the guidelines.

Decomposed — every stage open
LLM Perceptionreads raw input -> structured facts
checkable
Retrievalontology-guided
deterministic
Reasoningexplicit rules
readable

Every stage open. Bias has an address.

The fix follows from the diagnosis. By decomposing the reliability layer into checkable, deterministic stages, we can force the system to show its work. We separate the perception (what are the facts in this input?) from the retrieval (what are the rules for these facts?) from the reasoning (how do we apply these rules?).

Knowing bias vs eliminating bias

We may never fully "solve" bias in large language models. The latent space of a 1.8-trillion parameter model is too vast to ever be truly neutral. But for enterprise applications, the goal isn't to build a perfect model—it's to build an auditable system.

If a decision can be reduced to an explicit, auditable rule, it should be handled by a deterministic logic engine guided by an ontology. If it requires a degree of human judgment for which no policy yet exists, the honest answer is to keep a person in the seat.

Decision typeWho decides
Can be written as a rule (triage urgency, claims adjudication)Explicit rules — auditable
Requires judgment, no policy existsKeep a person in the seat

Source: Wong, Q.H. (2026). "Gender-Dependent Diagnostic Substitution in LLM Medical Triage." arXiv:2606.03641