In short
As data takes a more central role in litigation, legal teams should ensure expert evidence is built on reliable foundations. Understanding and defending underlying data can strengthen credibility and withstand scrutiny.
Every expert opinion rests on a foundation of evidence. Increasingly, that foundation is data.
The volume of data available in disputes has grown significantly in recent years. While this is evident across many industries, it’s particularly pronounced in matters involving construction, payroll remediation and funds tracing, where large, structuredand unstructured datasets often underpin expert analysis.
As that evidence base has evolved, so too have the expectations placed on expert witnesses.
It’s no longer enough to explain the conclusions. Experts are nowexpected to explain and defend the data behind them, or at the very least how that data has been used in their analysis and why it can be relied upon.
That shift is changing what good expert evidence looks like.
The foundation is under greater scrutiny
Traditionally, expert evidence has been tested on the strength of an expert’s reasoning and conclusions. Attention is turning to the information that underpins those conclusions. Where did the data come from? How was it extracted? Has it been transformed or filtered? Is it complete? Does it accurately reflect the issues in dispute?
If those questions can’t be answeredbythe expert with confidence and in a way that clearly demonstrates to the court the end-to-end process, the credibility of the evidence can begin to erode before the substance of the opinion is ever tested.
We’ve seen expert opinions challenged not because of the conclusions reached, but because the expert couldn’t adequately explain the data they relied upon or had manipulated the data in a way that wasn’t disclosed, couldn’t be explained or wasn’t repeatable.
The role of the expert is changing
Data is no longer simply an input into an expert’s work. In many matters, it has become evidence in its own right.
Data must be extracted, tested, reconciled, filtered or transformed before it can be relied upon. Those processes can involve assumptions and judgement calls, making it important that experts understand how the data has been prepared and can clearly explain why the resulting analysis is reliable.
This doesn’t mean every expert needs to undertake every aspect of the data analysis. It does, however, mean they need to understand the information they are relying on well enough to explain and defend it if challenged.
What this means for legal teams
Alongside technical expertise and industry experience, it’s worth considering whether an expert can confidently explain the entire journey of the data, from collection and preparation through to the analysis that informed their conclusions.
In more complex matters, it may also be appropriate to consider whether specialist data analytics capability is needed alongside traditional forensic or technical expertise.
These questions are best asked early. Once an expert report is being tested, uncertainty around the underlying data can become difficult to overcome.
Robust expert evidence starts well before a report is written.
Looking ahead
The volume and complexity of data will only continue to grow, and with it, the expectations placed on expert witnesses.
For legal teams, confidence in an expert’s opinion increasingly depends on confidence in the information that supports it. Understanding how that information has been collected, prepared and analysed is becoming just as important as understanding the conclusions themselves.
Strong expert evidence depends on more than a well-reasoned opinion. It depends on foundations that can withstand scrutiny.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
