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AI has bested chess and Go, but it struggles to find a diamond in Minecraft

AI has bested chess and Go, but it struggles to find a diamond in Minecraft


A new challenge tests AI’s ability to learn by watching

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Whether we’re learning to cook an omelet or drive a car, the path to mastering new skills often begins by watching others. But can artificial intelligence learn the same way? A new challenge teaching AI agents to play Minecraft suggests it’s much trickier for computers.

Announced earlier this year, the MineRL competition asked teams of researchers to create AI bots that could successfully mine a diamond in Minecraft. This isn’t an impossible task, but it does require a mastery of the game’s basics. Players need to know how to cut down trees, craft pickaxes, and explore underground caves while dodging monsters and lava. These are the sorts of skills that most adults could pick up after a few hours of experimentation or learn much faster by watching tutorials on YouTube.

But of the 660 entries in the MineRL competition, none were able to complete the challenge, according to results that will be announced at the AI conference NeurIPS and that were first reported by BBC News. Although bots were able to learn intermediary steps, like constructing a furnace to make durable pickaxes, none successfully found a diamond.

“The task we posed is very hard,” Katja Hofmann, a principal researcher at Microsoft Research, which helped organize the challenge, told BBC News. “While no submitted agent has fully solved the task, they have made a lot of progress and learned to make many of the tools needed along the way.”

Examples of some of the steps needed to mine a diamond in Minecraft from the MineRL training database.
Examples of some of the steps needed to mine a diamond in Minecraft from the MineRL training database.

This may be a surprise, especially when you think that AI has managed to best humans at games like chess, Go, and Dota 2. But it reflects important limitations of the technology as well as restrictions put in place by MineRL’s judges to really challenge the teams.

The bots in MineRL had to learn using a combination of methods known as imitation learning and reinforcement learning. In imitation learning, agents are shown data of the task ahead of them, and they try to imitate it. In reinforcement learning, they’re simply dumped into a virtual world and left to work things out for themselves using trial and error.

Often, AI is only able to take on big challenges by combining these two methods. The famous AlphaGo system, for example, first learned to play Go by being fed data of old games. It then honed its skills — and surpassed all humans — by playing itself over and over.

The MineRL bots took a similar approach, but the resources available to them were comparatively limited. While AI agents like AlphaGo are created with huge datasets, powerful computer hardware, and the equivalent of decades of training time, the MineRL bots had to make do with just 1,000 hours of recorded gameplay to learn from, a single Nvidia graphics processor to train with, and just four days to get up to speed.

It’s the difference between the resources available to an MLB team — coaches, nutritionists, the finest equipment money can buy — and what a Little League squad has to make do with.

It may seem unfair to hamstring the MineRL bots in this way, but these constraints reflect the challenges of integrating AI into the real world. While bots like AlphaGo certainly push the boundary of what AI can achieve, very few companies and research labs can match the resources of Google-owned DeepMind.

The competition’s lead organizer, Carnegie Mellon University PhD student William Guss, told BBC News that the challenge was meant to show that not every AI problem should be solved by throwing computing power at it. This mindset, said Guss, “works directly against democratizing access to these reinforcement learning systems, and leaves the ability to train agents in complex environments to corporations with swathes of compute.”

So while AI may be struggling in Minecraft now, when it cracks this challenge, it’ll hopefully deliver benefits to a wider audience. Just don’t think about those poor Minecraft YouTubers who might be out of a job.