There's a call for ACC to front up about how its computer-aided decision-making actually works and how clients can appeal particular decisions.

Otago University Associate Professor James Maclaurin says ACC uses a computer model to assist staff managing claims.

But he said the Artificial Intelligence and Law project he works on is aware of cases overseas where tools like this have turned out to be discriminatory.

He said that among the vague description by ACC is that the tool is being used to predict how long they expect a claim to be managed.

"It's very unclear exactly what that means, but what it might mean is that ACC is using this to minimise treatment times. In other words, it might really be a cost-saving device."

Mr Maclaurin said that, until more information is known, "we don't know," and wants ACC to explain the way this tool works so that clients can appeal particular decisions.

"The project that I work on ... is aware of cases overseas where tools like this have turned out not to be being used very well. In some cases, tools like this have turned out to be discriminatory."