The simple criterion for determining whether an expert is qualified to give expert (opinion) evidence is "Does he know what he is talking about?" It is a mistake to think that a technical expert or an academic will necessarily make a good expert witness. They may be able to give very strong factual evidence. An expert witness is there to assist the court which boils down to being able to express opinions in an understandable, reliable way that is independent of the interests of the party that is paying him.
We illustrate what we believe is required with an example in the form of three connected reports. As it happens we prepared these reports on a pro bono basis after a Small Claims hearing before a District Judge who adjourned the case, it appeared in the hope that the parties would go away and settle the matter between themselves.
After our three reports had been served and at the resumed hearing the Defendants said that they would no longer defend the case.
The reports have been anonymised. The Plaintiff (P) had taken his 386 PC to the Defendants (D) to be upgraded to a 486 PC. The Defendants had changed the appropriate chips correctly but as hardware specialists refused to have anything to do with software. In fact certain "settings" in the software have to be changed after such a hardware chip change.
At the resumed hearing the District Judge had thanked the Plaintiff for the excellent submission which, he said, had helped him to understand the case well. This is how it should be.
The reports are self-explanatory and entitled:
Note that it is of course inevitably possible to take exception on technical grounds to some of the points made and explanations given in the reports. Any who wish to take exception should bear in mind that the purpose of the reports is to assist the District Judge in making his determination. To that end the reports must not be either misleading or incomprehensible. A balance has to be struck, but that balance should not be fashioned to lead to an inevitable conclusion. The Defendant is protected in that he may both have his own expert to prepare a report and give evidence and he can cross-examine the author of the Plaintiff's reports. It is open to the District Judge to order a meeting of expert witnesses to agree what they are able to agree and to define their positions on anything they are not able to agree.
Expert witnesses are there to help the court or arbitrator by expressing opinions. They should say what the truly believe and not what they think the party paying them would like them to say.
Usually a judge will direct that a single joint expert is appointed. Usually an individual from a list agreed by the parties is appointed by the judge as a single joint expert.
A single joint experts report could well lead to a settlement of the dispute. If there is a trial it would be unusual for a single joint expert to be required to attend to give evidence.