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Conveying Opinions and Navigating Persuasive Language

As delay analysts, our job is to offer unbiased reports on delayed construction projects. The purpose is to determine the effect of delays and their causes.

One of the most difficult challenges as an expert, is presenting my opinions to third parties. Delay analysis can be complicated, and reports are often laden with jargon. Having the ability to speak effectively in this situation is a skill in and of itself.

This article explores the nuances of my role as an expert witness and my obligations under the CPR 35 rules.  I’ll look at the importance of informative and impartial language while navigating the limits of persuasive language.

The Obligation of Impartiality

As an expert witness, my duty is to provide an unbiased analysis and opinion. The credibility of my report hinges upon its impartiality, and it is essential to approach the analysis with an open mind. A good expert must examine all relevant facts and evidence. Regardless of who is paying the fee, an expert cannot favour either party. This impartiality requires that my opinions and conclusions are grounded in objectivity, which will strengthen their credibility before an adjudicator, court or tribunal.

CPR 35 Compliance

Expert witnesses must adhere to the Civil Procedure Rules (CPR) 35 when preparing reports for litigation. These rules dictate the standards and requirements for expert evidence. Experts should be mindful of their obligations to present “…objective, unbiased opinions on matters within their expertise, and should not assume the role of an advocate” (see 2.2 of the CPR 35 practice direction). Following these guidelines will ensure the integrity and admissibility of expert evidence.

Clarity and Conciseness

Effective communication is crucial in conveying complex delay analysis. It’s important to prioritise clarity and conciseness.

It is challenging, but not impossible, to present technical information which is accessible to a non-expert audience. I try to accomplish this by ensuring the report is clear and concise. The goal is to make each sentence as lean as possible, avoiding unnecessary filler and relying on clear language. Where appropriate, the use of visual aids can be really beneficial to third parties. Exhibits such as photographs, graphs and bar charts can aid a better understanding. Using straightforward language is also helpful, avoiding complex words and jargon.

The Use of Persuasive Language

While impartiality is paramount, I must also possess the ability to be persuasive in my opinions. Striking a balance between the two is vital, as appearing biased could undermine my credibility. When using persuasive language, it is crucial that it is firmly rooted in the evidence and facts presented. This is most easily achieved by articulating logical arguments which are rooted in the facts. In my evidence, I explain the cause-and-effect (or more frequently, effect and cause!) relationship between delays and their likely causes. This approach enables me to present a compelling case that remains grounded in objectivity.

I often have access to the expert reports prepared by the opposing party, where repetition, hyperbole, and even irony are commonly employed tactics. Some more experienced experts may add these subtly, maybe to great effect. However, the majority who use these approaches sound like advocates. In my opinion, it is best to avoid using this type of language entirely.

Utilising Objective Terminology

Objective terminology is instrumental in avoiding bias. The language should be precise, neutral, and focused on the factual aspects of the delays and their causes. The use of definitive terms, such as “based on the evidence,” “it is likely,” or “as per the industry standards,” helps reinforce objectivity and credibility. As always, these opinions must be supported by the relevant facts.

Maintaining integrity requires refraining from speculative language. From a reader’s perspective, the expert should be confident in their opinion, but they must be careful not overstep the mark. It is crucial to avoid making assertions or declarations without sufficient supporting evidence.

Acknowledging Limitations and Uncertainty

While conveying opinions, an expert must acknowledge the limitations and uncertainties. Construction projects are complex endeavours, encompassing a vast number of interacting variables. It is often extremely challenging to determine precise causes of delays.

Acknowledging the uncertainties and/or gaps in evidence helps to maintain credibility. Try to provide a transparent assessment of the available evidence, and guard against any perception of bias.


The expert should always be mindful of their CPR 35 obligations. Sometimes it is worth reading the declaration at the beginning and during the analysis – not just signing them at the end!

Striking the right balance between persuasion and objectivity requires a cautious approach. This is facilitated by employing objective terminology and logical arguments. An expert report should be peer-reviewed by a third party, as they can identify instances where they tread too close to the line. Also, by acknowledging limitations and uncertainties, the expert can foster credibility, whilst ensuring to never stray from the facts.

Should you need support on any of the issues in this article, don’t hesitate to get in touch with the team.