An expert witness testifying in a landmark lawsuit against poker machines "copied and pasted" parts of his evidence from unattributed sources, including Wikipedia, a court has heard.
In a tense hearing last week, professor and clinical neuropsychologist Murat Yucel was cross-examined at length by lawyers for ASX-listed pokies maker Aristocrat about whether sections of his expert report had been lifted almost word for word.
Professor Yucel was giving evidence about the neuroscience of compulsion and addiction, when Aristocrat's barrister, Peter Wallis, drew his attention to blocks of text in his testimony that he suggested had been "copied verbatim" from other sources, but not attributed.
"That appears to be exactly the same language in your report as in the paper I've just taken you to, doesn't it?" Mr Wallis said.
"Very similar, yes," replied Professor Yucel. "I remember seeing that report."
"But you didn't attribute that portion of the report, did you?" Mr Wallis said.
Professor Yucel went on to tell the Federal Court he had not believed it was necessary to reference the source of "descriptions" included in his report in the same manner that he would reference "empirical findings".
"This is not an empirical finding," he said. "It's a description of a very, very well known, very well-described model of addiction."
He also said he did not believe his expert report was required to meet the same referencing standards as academic papers, and said his report had been prepared in a much shorter timeframe than academic papers, which "may take months".
Professor Yucel was in court after being called as a witness by the legal team of former pokies addict Shonica Guy, who is taking on Aristocrat and casino giant Crown Resorts in an unprecedented lawsuit.
The legal action claims that the design of the Dolphin Treasure poker machine - including its uneven spread of symbols and the fact that the final reel has more symbols than the rest, allegedly making losses seem like "near misses" - is deceptive and misleading to gamblers.
It is also alleged that gamblers are misled by overall losses that are often disguised as wins, and by the machine's information about the theoretical rate of "return to player". Professor Yucel was one of several expert witnesses called by the plaintiffs.
In the courtroom last week, Professor Yucel conceded that another section of his evidence, concerning the psychology of the "illusion of control" was "probably a copy and paste" from a Wikipedia entry on the same subject.
"So your Honour should understand that that portion you have copied from Wikipedia?" Mr Wallis asked him.
"It looks like it, yes," Professor Yucel said.
"It seems like in that particular instance it would make sense to acknowledge the Wikipedia, I agree."
Lawyers for Aristocrat and Crown Resorts are expected to criticise the credibility of Professor Yucel's evidence during closing submissions, which begin on Tuesday morning.
Justice Debbie Mortimer told Professor Yucel that closing submissions often included criticisms of witnesses.
"I think it would come as no surprise to you to expect that the two respondents in this case will criticise your evidence, and they will do so in a way that is likely to invite me to make findings that may affect your professional reputation," she said.
Professor Yucel, who has published more than 280 academic papers, said he may not have understood the requirements of the expert witness code of conduct.
He said had intended for his expert report to provide the court an "information-type orientation" rather than attempting to claim any ownership over the ideas or models.
"So, I think, in that regard, I have given myself some freedom of taking things where I felt it was very clearly described and putting them in because I felt that would actually be helpful to your Honour, rather than try to reword them and mess with them," he said.
