ISO/IEC 17025 clause 7.8.7: control opinions and interpretations

What clause 7.8.7 requires in practice

Clause 7.8.7 allows a laboratory to give opinions and interpretations, provided it keeps them under control. Four conditions apply. Only personnel authorised for that activity release such statements. The laboratory documents the basis on which each opinion or interpretation was made. In reports, the opinion rests on the results the tested or calibrated item produced, and it is labelled plainly as an opinion or interpretation so nobody mistakes it for a measured result. Where an opinion is given in conversation with the customer, a record of that conversation is kept.

A note in the clause also requires the laboratory to keep opinions and interpretations distinct from statements of inspection, from product certification statements and from conformity statements under clause 7.8.6.

In short, the clause separates what was measured from what the laboratory thinks it means, and it requires that the second be competent, supported and traceable.

Separate the result from the interpretation

A measured value, a statement of conformity and a professional interpretation are not interchangeable. An interpretation explains the significance of results in context. It should not be presented as an additional observation or as a conclusion extending beyond the available evidence.

The standard also distinguishes these communications from inspection statements and product certification. A laboratory's technical expertise does not automatically authorise it to imply that a product has received a separate certification or that an inspection scheme's requirements have been fulfilled.

Establish competence and authorisation

Identify which personnel may provide particular opinions or interpretations and the competence needed. Routine report-release authority does not automatically establish expertise for every interpretive question. Consider the technical field, application and limits of the evidence.

Document the basis for the conclusion, including relevant results and reasoning. The required record need not follow one prescribed format, but it should make the connection understandable to a competent reviewer. An unsupported phrase such as “suitable for all uses” is not made defensible by a senior person's signature.

Preserve verbal interpretations too

Where an opinion or interpretation is communicated through direct dialogue with the customer, retain a record of that dialogue. Telephone advice can influence decisions just as much as a written report. Ensure personnel know when a conversation moves beyond explaining a number into an interpretive statement.

Coordinate with confidentiality, contract review and report controls. If the customer requests advice beyond the laboratory's competence or available evidence, clarify the limit and the appropriate route for further assessment instead of filling the gap with confident speculation.

Why controlling opinions and interpretations matters

Customers often ask laboratories what a result means, not only what it is. That conversation is valuable, but it is also where a laboratory can drift into advice it cannot support, or into language that sounds like approval of a product.

Controlled interpretation protects the customer from decisions made on weak reasoning, and it protects the laboratory from liability for casual remarks. It also strengthens the commercial offer: a laboratory that explains its findings with a clear evidence trail is more useful than one that only issues numbers, and an assessor will see that the added value is competently managed.

How to implement clause 7.8.7

Start by finding out where interpretation already happens, in reports, emails and telephone calls, before writing any rule about it. The aim is a short, workable routine that staff will actually follow. Keep it proportionate: a laboratory that offers little interpretation needs little machinery, but it still needs clear authority and a trail.

1. Ask technical staff and customer-facing staff where customers request views on results, and collect typical examples.
2. Define which kinds of interpretation the laboratory is willing to offer, and which fall outside its competence or evidence.
3. Name the people authorised for each kind of interpretation and record the competence behind each authorisation.
4. Set a simple way to record the basis of an interpretation, such as the results used and the reasoning, so a reviewer can follow it.
5. Mark interpretations in reports so they are visibly separate from measured results and conformity statements.
6. Agree how verbal advice is noted, for instance a short call record, and brief staff on the point at which explaining a number becomes interpreting it.

Two illustrative interpretations

Evidence and common weaknesses