The expert witness and the common framework

An expert witness in a valuation matter carries two obligations at once: to assist the court or tribunal, and to produce an opinion that can survive examination by an opposing expert who may have been trained in a different jurisdiction, under a different professional tradition. A common framework does not decide the case — but it gives both experts, and the tribunal between them, a shared language in which the real disagreements can be found.

A shared frame of reference

The IVSC has set out why the International Valuation Standards (IVS) matter to lawyers, judges, expert witnesses and arbitrators: credibility in cross-border disputes, consistency between experts, and principles-based flexibility that adapts to different assets and contexts. Because IVS are used as a framework in more than 100 countries, an expert who structures an opinion around them is working in terms that opposing experts, instructing counsel and tribunals are increasingly likely to recognise.

Defining the question before answering it

Many disagreements between experts turn out, on inspection, to be disagreements about the question rather than the answer. The IVS General Standards address this directly. IVS 101 Scope of Work requires the engagement to be defined; IVS 102 Bases of Value requires the expert to be explicit about what kind of value is being measured — and a conclusion is only as useful as the fit between its basis of value and the question the tribunal must decide. When two experts state their bases of value clearly, a tribunal can see immediately whether they are answering the same question or talking past one another.

Documentation that can travel

IVS 106 Documentation and Reporting completes the chain: the route from inputs and assumptions to conclusion should be recorded so that the reasoning can be followed by someone who was not in the room. For an expert witness this is not bureaucracy; it is the substance of cross-examination resilience. An opinion whose assumptions are identified, whose data sources are stated and whose judgements are explained gives opposing counsel less room to suggest that the conclusion was reached first and justified afterwards.

Candour about uncertainty

Experts sometimes fear that acknowledging uncertainty will be read as weakness. The IVSC’s Valuation Risk Working Group argues the opposite in its perspectives paper on managing and communicating value uncertainty: value uncertainty is inherent in valuation, not a failure of it, and is distinct from valuation risk — errors of process, which can and should be mitigated. Even a fully IVS-compliant valuation may yield a range of credible outcomes, and transparency about that range strengthens confidence in the conclusion. An expert who can explain why uncertainty exists, how it was managed and what it means for the figure offered is in a stronger position than one defending a point estimate as though it were a fact.

What tribunals commonly probe

The standards suggest where examination tends to concentrate. The questions below are the ones tribunals and opposing counsel most commonly put.

None of this replaces the expert’s own judgement — the standards frame the work; they do not perform it. But a common framework turns a contest of assertions into a comparison of reasoning, which is precisely what tribunals need expert evidence to be.