An Opinion and a Conclusion Are Different Things

The difference between a report that persuades and one that does not is rarely the conclusion, which is usually the one the instructing party hoped for. It is whether the reader can see how the writer got there, and whether they could get there themselves.

What a reasoned opinion shows

The material relied on. Everything examined, listed rather than summarized, so that a reader knows what was in front of the writer and, equally importantly, what was not.

The assumptions made. Facts taken as given rather than found, stated separately and clearly, because an opinion resting on an assumption falls with it if the assumption fails.

The method applied. What was done to the material, in enough detail that somebody with the same expertise could follow it and, in principle, repeat it.

The steps between. The reasoning that moves from material to result, which is the part that allows a decision-maker to accept some of it and not the rest.

The alternatives considered. Other explanations examined and rejected, with the reason, which is what distinguishes an analysis from an argument for a predetermined result.

All of it in a defined structure. The elements are not optional decoration but the substance of the document, and the shape they take is set out in what an expert report must contain.

Why bare conclusions fail

There is nothing to agree with. A reader presented only with a result must accept the writer's authority or reject it, and decision-makers are reluctant to do the first.

They cannot be partially adopted. Where reasoning is visible, a decision-maker can accept the analysis and differ on one step; where it is not, the whole opinion stands or falls together.

They cannot be tested. Cross-examination on a conclusion produces a restatement of the conclusion, whereas cross-examination on reasoning produces something useful either way.

Some jurisdictions exclude them. An opinion offered without any basis is inadmissible in several systems, on the ground that assertion by a qualified person is not evidence.

They invite the obvious question. A reader who cannot see how a conclusion was reached asks why not, and the answers available to that question are all unattractive.

The route is what gets examined. Where a challenge is brought against an opinion, the material and the method are what the argument is about, as the basis of an opinion and its weak points describes.

Assumptions and findings, kept apart

An expert does not find facts. Disputed facts are for the decision-maker, and an expert who resolves them has stepped outside their function and into somebody else's.

So assumptions are stated as such. An opinion given on the basis that a particular account is accurate is a conditional opinion, and saying so protects it rather than weakening it.

Alternative assumptions are better still. An opinion addressing both versions of a disputed fact remains useful whichever way the decision-maker resolves it, and is far more valuable for that.

The instructing party supplies assumptions. Which means the letter of instruction becomes part of the material, and it is frequently disclosable alongside the report itself.

Unstated assumptions are the danger. An opinion that quietly assumes something contested contains a hidden dependency, and its discovery undermines everything built on it.

Acknowledging limits

Stated limits strengthen an opinion. A writer who identifies what their material cannot establish is demonstrating judgment, and decision-makers respond to that far better than to uniform confidence.

Ranges beat single figures. Where a value or an interval genuinely cannot be pinned down, a range with an explanation is more credible than a precise figure with none.

Say what further material would help. Identifying what would resolve a remaining uncertainty is useful to everybody and demonstrates that the analysis is genuinely open.

Distinguish confidence levels. An opinion whose parts are held with different degrees of certainty should say so, rather than presenting everything at the same pitch.

Overclaiming is the common failure. A report asserting more than its material supports is vulnerable at exactly the point an opponent will look, and the vulnerability is self-inflicted.

Reading a report critically

Find the route. Trace the reasoning from material to conclusion, and note wherever a step is missing, because that gap is where the report is weakest.

Separate assumption from finding. Every fact treated as given rather than examined is a dependency, and each one is a place the opinion can be attacked without touching its expertise.

Check what was not examined. The list of material considered is as informative as the analysis, and material that was available and not looked at is a serious question.

Look for the alternatives. A report that considers no other explanation is either dealing with a very simple question or has not asked one, and both are worth exploring.

Compare the summary with the body. Executive summaries routinely state conclusions more firmly than the analysis behind them supports, and the difference is worth putting to the writer.

Two reports rarely differ over nothing. Where a second opinion reaches a different result, the disagreement almost always sits in the assumptions or the material rather than in the expertise, which is the subject of two experts who disagree.

The distinction between showing a route and announcing a destination explains most of the difference in weight between expert reports. Both may be written by properly qualified people and reach defensible results, and only one can be engaged with.

The commercial pressure runs the other way, because instructing parties want clarity and short reports. A report that hedges appropriately and shows its working reads as less decisive and is considerably harder to displace.

Assumptions deserve particular care because they are where reports fail most often and most avoidably. An opinion resting silently on a contested fact collapses when that fact is resolved differently, and stating the dependency prevents that entirely.

Acknowledged limits are counter-intuitively persuasive. A writer who says what their material cannot establish demonstrates that they distinguished the two, which is precisely the quality a decision-maker is looking for.

For anybody reading a report from the other side, the productive approach is to trace the route rather than to argue with the destination. Missing steps, unexamined material and hidden assumptions are all more attackable than the conclusion itself.