QuestionAI GovernanceFinancial Servicesvendor risk

What datasets were used to train or fine tune the models in your service?

23 April 2026
Answered by Rohit Parmar-Mistry

Short answer

Ask the vendor what it can disclose about pretraining and fine-tuning data, exclusions and known limitations. Where source detail is unavailable, use contract evidence and testing on your own cases to decide whether the use is acceptable.

Detailed answer

Record and Assess Gaps in the Vendor's Training-Data Evidence

Ask the supplier what it can disclose about pretraining and fine-tuning data, exclusions and known limitations. Record what remains unknown, compare the answer with the contract and technical evidence, and test the proposed use before deciding which restrictions or further assurance are needed.

This question matters because model performance is shaped by data long before your team ever writes a prompt. If the vendor cannot describe the origin, quality, scope, and limitations of training or fine tuning data, it becomes much harder to assess bias risk, explainability, legal exposure, and whether the system is even suitable for your workflow.

That is especially important in regulated and professional environments where weak model provenance can quickly become an operational and accountability issue.

The answer should be specific enough to support real due diligence

Identify which information the team needs to assess the proposed use. A supplier’s description should make the relevant sources, controls and limitations understandable, but it is not proof on its own that deployment is safe.

A useful answer should cover:

  • the broad sources of pre-training data
  • whether any proprietary, licensed, synthetic, customer, or public datasets were used
  • whether sector-specific fine tuning data was used
  • what kinds of data were excluded
  • what quality controls, filtering, or curation steps were applied
  • what known dataset limitations the vendor is aware of

If the answer is only that the model was trained on a mixture of high-quality sources, ask what source types, checks and known limitations support that description. Record an unanswered question rather than treating the wording as assurance.

Assess model and vendor risk before procurement

Why dataset provenance matters more than many buyers realise

Training data is not just a technical background detail. It shapes how the model generalises, what blind spots it carries, and what kinds of errors are more likely to appear in real use.

Use the issues below as questions for the supplier review and testing. Missing provenance detail may leave them unresolved; it does not by itself prove that a particular failure has occurred:

  • Bias risk: the model may reflect skewed or incomplete source material.
  • Sector mismatch: the system may perform poorly in legal, financial, insurance, or professional workflows it was not prepared for.
  • Copyright and licensing risk: unclear sourcing can create downstream contractual or legal concern.
  • Explainability weakness: teams may struggle to justify why the system behaves as it does.
  • Model drift blind spots: without understanding the training base, it is harder to judge whether later updates create new failure modes.

This is why training data questions belong in procurement and governance review, not just in technical vendor selection.

The red flags buyers should watch for

Check whether the answer addresses the question and is consistent with the supplier’s documentation. The signs below identify follow-up work, not a substitute for assessing the evidence.

Warning signs include:

  • the vendor avoids the question entirely and redirects to marketing language
  • the sales answer conflicts with legal or technical documentation
  • the vendor cannot distinguish pre-training from fine tuning
  • there is no clear statement on customer data exclusion or inclusion
  • the vendor cannot explain dataset controls for sector-sensitive use cases
  • limitations are described as negligible or not relevant without evidence

Ask the supplier to resolve inconsistencies and document any gaps it cannot answer. Decide how each gap affects the proposed use rather than inferring the supplier’s overall governance quality from its sales response.

Build a stronger AI vendor due diligence process

What firms should ask in follow-up

The first question opens the door, but the follow-up questions are what make the answer useful.

Buyers should ask:

  • What categories of data were used for pre-training versus fine tuning?
  • Were any regulated, client, or sector-specific datasets used?
  • How was data quality assessed and harmful content filtered?
  • What known limitations or bias patterns have you identified?
  • How often is the model updated and does the data basis change over time?
  • What evidence can you provide that the model is suitable for our use case?

Check the suitability evidence against the firm’s own task, data and review process. A broad benchmark or general demonstration may not cover the workflow being proposed.

How this should affect implementation decisions

Where the answer is incomplete, identify which uncertainties matter to the proposed deployment and who can decide whether they are acceptable. Use the controls below as options to assess, not as automatic permission to proceed.

For example, firms may decide to:

  • limit the tool to low-risk internal use cases
  • require human review for all client-facing or regulated outputs
  • prohibit use on sensitive datasets until further assurance is available
  • add stronger testing around bias, quality, and exception handling
  • review the vendor more frequently when model updates occur

Record the selected limits, tests and review responsibilities in the deployment process. Revisit them when the supplier changes the model or provides evidence that alters the assessment.

A simple decision rule for buyers

If the training-data answer leaves a material question unresolved, record the gap and assess whether a narrower use, further evidence or a pause is needed. Do not assume additional controls can compensate for every unknown.

That may mean pausing procurement, narrowing the use case, or increasing human oversight. What it should not mean is accepting an opaque answer and hoping implementation will solve the problem later.

Turn vendor diligence into workable deployment controls

Conclusion

Request the source categories, exclusions, controls and limitations relevant to the intended task. Distinguish verified records, supplier assertions and unavailable detail, then have the responsible reviewers decide what each gap prevents them from concluding.

Where provenance is insufficient for the proposed high-stakes use, leave the deployment decision open. Document what further evidence or change to the use would be needed for the relevant reviewers to decide.

Need a safer AI route for your firm?

If this article reflects a live decision in your practice, the useful next step is to map the workflows, confidentiality risks, supplier controls and governance gaps before tools spread informally.

Frequently asked questions

Do buyers need a full list of every training dataset?

Decide which detail is needed for the proposed use rather than assuming every dataset must be listed. Ask for the relevant source categories, controls and limitations, and record where missing detail prevents the assessment.

Why does training data matter if the model performs well in testing?

Tests show performance on the cases tested, not the answer to every provenance, licensing or governance question. Review those issues separately and check whether the test cases represent the proposed deployment.

Is this only relevant for custom fine tuned models?

Ask the questions for foundation models and supplier-managed services as well as custom fine-tuning. Record which parts of the model and data the firm can inspect or control, and which depend on supplier evidence.

What if the vendor says the data is proprietary and cannot be disclosed?

Ask which source categories, controls, exclusions and limitations can be disclosed without exposing proprietary detail. Record what is withheld and assess whether the available evidence is enough for the proposed use.

Should unclear dataset provenance always block procurement?

Assess the material gaps and the proposed use together. The decision may be to seek evidence, narrow the use or pause procurement; stronger review alone is not proof that an unresolved provenance risk is acceptable.

Discuss your next step

Talk through your situation with Rohit, or take the assessment if you need a first read.