On a spring day in Adelaide, 350 randomly selected South Australians stood in the city's Convention Centre and engaged in a robust debate on a proposed nuclear waste management site.

It was hardly a sexy topic - public debates often aren't - but the outcome would decide whether the public would welcome a decision to turn a site in the state's northern reaches into a dumping ground for nuclear waste.

The group, or citizens' jury as it's known, was one of the first of its kind.

Not only was the South Australian government making a very public showing of its commitment to deliberative democracy, it was also one of the largest citizens' juries the world had ever seen.

Typically citizens' juries number around 50 people, but this group was seven times that figure.

A co-chief executive of the group tasked with facilitating the experiment, Democracy Co's Emma Fletcher, recalls it being a very exciting time - although the large spread of voices and opinions made the process challenging.

"It was very empowering for people," she says. "But it's really hard for people to build relationships in a group that size."

Trust plays a key role in deliberative forums like the one that occurred in South Australia in 2016, and the numerous smaller ones around the country since.

But it's something Ms Fletcher says was hard to achieve in a large group. Scepticism between citizens, facilitators and experts offering information runs rampant.

"Governments would like to do juries that size because it sounds big and sounds powerful, but it can seriously compromise the process in our view," she says.

"We've never done a jury that size again and we will never do a jury that size again."

The jury ultimately handed down a report against the nuclear waste proposal, a decision arrived at with a two-thirds majority. The South Australian government shelved the idea for another day.

While Ms Fletcher has some reservations about the process, it was heralded as a success for deliberative democracy.

In Canberra, a public consultation attempt has been criticised for being exactly the opposite.

A controversial redevelopment project for the Australian War Memorial this week received its final tick of approval from the National Capital Authority, and will soon begin early works.

It followed a months-long public consultation process, where some 600 submissions expressed views on the $500 million expansion. An overwhelming 590 submissions were against the proposal.

Deliberative democracy expert Dr Simon Niemeyer has researched models around the world that work to balance public input with the reality of government policy and implementation.

He says on the face of it, the war memorial's process doesn't sound like one that was meant to work in that way.

"It's that classic approach where you have your decision model, you run the processes and you develop a sort of sphere of legitimacy around having ticked those boxes," Dr Niemeyer says.

But the authority's approval process was never meant to be a shining example of democracy. Instead, its remit extends to ensuring works within Canberra, and specifically within the land it manages, are in accordance with the National Capital Plan - a strategic plan that keeps the fabric of the national city consistent.

Dr Niemeyer suggests the public should have been brought in when plans were first being developed by the government, in order to have avoided the bitter taste opponents are now left with over its handling.

Both he and Ms Fletcher are keen advocates for these sorts of processes becoming a natural part of Australian political life, replacing outdated forms of one-way decision-making.

Box-ticking exercises, they both say, lead to declining trust in government, and could easily be avoided by bringing the public on board from the outset.

Labor member for Fenner Dr Andrew Leigh is also a strong supporter of rethinking the way governments conceive, ideate and implement new policies and projects.

"Even in democracies like Australia, we've seen a decline in the share of people who feel confidence in the way in which the government is operating," he says.

"Deliberative democracy isn't a complete answer to that, but it's certainly part of the answer."

But while the process offers a possible solution to the crisis of confidence, it doesn't always work seamlessly.

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When Ms Fletcher reflects on the South Australian experiment, she doesn't look back on it as a success.

Success, as she defines it, is based on a well-executed deliberative process, rather than fulfilling a government objective. When a democratic experiment does achieve both of those goals, however, evidence-based and informed policy is the usual outcome.

And when the public is considered from the outset, rather than being an afterthought, meaningful and considered policy tends to be far more likely.

"That's the thinking process public servants need to go through, and the process that they don't go through," Ms Fletcher says.

"I was one of those public servants who never did that thinking.

"And it took a bit of a revolution for me to realise that the way I was working was wrong and to change the way I worked."

Dr Leigh and a team of researchers from the University of Canberra's Centre for Deliberative Democracy and Global Governance, along with other like-minded organsations, are running town halls on specific issues voted on in Parliament.

He's just one member among 151, but he says he's hoping the model will eventually catch on.

"There are issues in which citizens' juries can work really well," Dr Leigh says.

"The more the discussion around deliberative democracy strengthens, the more there'll be a recognition that this needs to be an effective part of modern government."