SILICON VALLEY -- Google has trained a computer to beat professional go players, opening the door to new applications and ethical concerns as artificial intelligence draws closer to matching human thinking.
The U.S. tech giant presented its findings in Wednesday's issue of Nature. Though a computer managed to topple the world chess champion in 1997 and defeat the top women's shogi player in 2010, Google's Alpha Go program is the first to triumph over professional go players under official rules.
Tougher than chess
The go board is larger than that used in chess or shogi, creating possible scenarios numbering 10 to the 360th power. Anticipating and solving all possible board combinations is impossible even for today's most advanced computers, and many researchers had predicted that a program capable of besting pro players was at least 10 years off.
Google's go AI bypassed that problem with deep learning, a technology that mimics human neural pathways and learning processes. Rather than working through the possible scenarios by brute force, the program considers the board as a whole, drawing on accumulated experience to choose its next move. The company has used such technology before, presenting last year its Deep Q-network algorithm letting computers master electronic games by analyzing pixel and score data over repeated plays.
For its go project, Google collaborated with pro players to teach the computer 30 million plays, letting it predict humans' moves with 57% accuracy. The AI then was put through several million matches against itself, forcing it to work out winning strategies by experience. Its ability to select the ideal move by analyzing the state of the board is now nearly equal to a human's ability to act on skill and intuition.
The program can beat existing go software 99.8% of the time, and it won all five games against reigning European champion Fan Hui in October. The AI will face another five-game challenge in March, when it goes up against Lee Se-dol, one of the world's top players.
The question now is where Google will direct its AI efforts next. Games are an excellent arena in which to develop and test AI, but the goal is to turn such technology toward solving real problems facing society, said Demis Hassabis, Google's AI chief. The priority is on developing robust multipurpose AI tech, he indicated.
Deep learning is particularly promising, given its ability to process visual and audio information in a manner resembling human perception by finding patterns in large data sets. Recent research has sought to apply the technology in diverse fields, using it to control robots' movements and analyze medical image data to help diagnose patients. Simple forms are already at work in today's tech, such as voice recognition software on smartphones. The dawn of AI capable of replicating human professionals' intuition would drastically expand the current slate of applications.
Yet researchers also are growing more cautious as AI advances. Though Google is pleased to have overcome a major challenge for AI, Hassabis said, the company is aware of the ethical issues surrounding the technology. Academics and other public figures have said that unchecked development potentially could lead to AI programs hostile to society as a whole.
As with "any powerful new technology," developers of AI must "take seriously our responsibilities" and "have ethical concerns at the top of our minds," Hassabis told the BBC last year. Google has established an AI ethics board to ensure those concerns are addressed. Now that technology has won out against humanity in one of the ultimate game-based challenges, the focus of research must turn to cooperation between man and machine.