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

If a vendor cannot explain training data, you have a governance problem

One of the most useful due diligence questions in AI procurement is also one of the most revealing: what datasets were used to train or fine tune the models in your service?

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

Most buyers do not need the vendor to disclose every technical detail. They do need enough clarity to judge whether the model was developed responsibly and whether it is safe to deploy in context.

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 vendor responds with a vague statement such as trained on a mixture of high-quality sources, that is not meaningful due diligence. You need enough substance to assess fitness, risk, and governance impact.

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.

For example, unclear dataset provenance can create problems such as:

• 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

In practice, the most concerning answer is not always a direct refusal. Often it is polished ambiguity.

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

Those signals usually point to weak governance maturity, not just incomplete messaging.

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?

That last question matters. A model can be impressive in general and still be poorly suited to your actual business environment.

How this should affect implementation decisions

If the vendor gives a partial but credible answer, the next step is to decide what that means for deployment. Not every uncertainty blocks procurement, but it should shape control design.

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

This turns procurement due diligence into an actual operating model rather than a one-off questionnaire exercise.

A simple decision rule for buyers

If the vendor cannot explain, at a meaningful level, what data shaped the model and what constraints follow from that, you should assume more control is needed, not less.

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

Buyers should ask what datasets were used to train or fine tune an AI model because dataset provenance affects bias, suitability, explainability, and legal exposure. A credible vendor should be able to describe data sources, exclusions, controls, and known limitations clearly enough to support real risk assessment.

The practical standard is straightforward. If model provenance is too vague to review, it is too vague to trust in a high-stakes workflow.

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.

• Map AI risk and opportunity
• Put usable AI governance in place
• Roll out AI with privacy and supplier controls
• See AI support for legal services