There is a general rule that courts will reject the evidence of a person’s ‘opinion’.

The most well known exception to this rule is that which permits experts, in tightly constrained circumstances, to give opinion evidence.

This is a controversial area and much has been written and said about it over the past five years.

One of the important principles established by the courts is that an expert’s opinion is useless unless the rationale for that opinion is explained, and the facts underlying the opinion are made clear. However eminent the person, the bare opinion of that expert without more will be of no use.

Judges and tribunals have traditionally been sceptical of expert evidence. This was reflected in a survey conducted for the Australian Institute of Judicial Administration in mid 1997 which found that:

... some seventy percent [of Judges]—had had occasions where they had felt that they had not understood expert evidence in the cases before them. Some twenty percent of judges responding to the survey said that they ‘often’ experienced difficulty in evaluating opinions expressed by one expert as against those expressed by another.1

Reflecting this scepticism, the courts have developed, and continue to develop, a number of procedures and devices in an attempt to reign in the (perceived) inappropriate use of experts. These procedures and devices have included:

  • restricting legal professional privilege and exposing the communications with experts (including, in some jurisdictions, communications with experts who are not called to give evidence) to production and disclosure
  • refusing to allow expert evidence unless the court has been notified at an early stage of the intention to call such evidence
  • requiring experts to meet before giving evidence in an endeavour to identify areas of agreement and disagreement
  • using practice directions which require experts to be independent and set out a number of matters to which the expert must give their attention before preparing a report and giving evidence
  • insisting that parties use a single expert rather than permitting each party to call its own expert
  • the use of a single court appointed expert, and
  • getting experts to give their evidence together (concurrent evidence) rather in the traditional seriatim manner.

Expert evidence has been the subject of recent law reform inquiries2 and is one of many issues currently under consideration by the Victorian Law Reform Commission in its Civil Justice Review.3

The New South Wales Supreme Court has recently issued a practice note for its Commercial and Technology and Construction Lists which states that:

The use of a single expert or a Court Appointed Expert and/or the concurrent evidence of experts is encouraged in suitable cases.

It is thus no longer the case that each party to a commercial dispute can expect that it will be able to obtain evidence from an expert of its choice.

This is an area of litigation practice which is likely to evolve. Further notes will issue as developments occur.


1. See

2. Australian Law Reform Commission Report 89,Managing Justice; New South Wales Law Reform Commission Report 109,Expert Witnesses, June 2005; and the Uniform Evidence Law Report (2005) comprising ALRC Report 102, NSWLRC Report 112 and VLRC Final Report December 2005.

3. Practice Note No SC Eq 3 (which commenced on 1 September 2006).

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.