Less than two years after Google dismissed two researchers who criticized the biases built into artificial intelligence systems, the company has fired a researcher who questioned a paper on the abilities of a particular type of artificial intelligence used in making computer chips.
The researcher, Satrajit Chatterjee, led a team of scientists in challenging the celebrated research paper, which appeared in the scientific journal Nature last year and said computers were able to design certain parts of a computer chip faster and better than human beings.
Dr. Chatterjee, 43, was fired in March, shortly after Google told his team that it would not publish a paper that rebutted some of the claims made in Nature, adding that four people were familiar with the situation who were not able to speak openly on the matter. Google confirmed in a written statement that Dr. Chatterjee had been “terminated with cause.”
Google declined to elaborate about Dr. Chatterjee’s dismissal, but it offered a full-throated defense of research he criticized and of its unwillingness to publish his assessment.
“We thoroughly vetted the original nature paper and stand by the peer-reviewed results,” Zoubin Ghahramani, a vice president at Google Research, said in a written statement. “We also rigorously investigated a subsequent submission of technical claims, and did not meet our standards for publication.”
Dr. Chatterjee’s dismissal was the latest example of discord in and around Google Brain, an AI research group considered to be a key to the company’s future. After spending billions of dollars to hire top researchers and create new types of computer automation, Google has struggled with a wide variety of complaints about how it builds, uses and portrays those technologies.
Tension among Google’s AI researchers reflects much larger struggles across the tech industry, which faces myriad questions over new AI technologies and the thorny social issues that have entangled these technologies and the people who build them.
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The recent controversy also follows a familiar pattern of dismissals and wrongdoing of dueling claims by Google’s AI researchers, a growing concern for a company that has bet on its future infusing artificial intelligence into everything it does. Sundar Pichai, the chief executive of Google’s parent company, Alphabet, has compared AI to the arrival of electricity or fire, calling it one of humankind’s most important endeavors.
Google Brain started as a side project more than a decade ago when a group of researchers built a system that learned to recognize cats in YouTube videos. Google executives were so taken with the prospect that machines could learn skills on their own, they quickly expanded the lab, establishing a foundation for remaking the company with this new artificial intelligence. The research group became a symbol of the company’s grandest ambitions.
Before she was fired, Dr. Gebru was seeking permission to publish a research paper about how AI-based language systems, including technology built by Google, may end up using the biased and hateful language they learn from text in books and on websites. Dr. Gebru said she had grown exasperated over Google’s response to such complaints, including its refusal to publish the paper.
A few months later, the company fired the other head of the team, Margaret Mitchell, who publicly denounced Google’s handling of the situation. Gebru. The company said Mitchell had violated its code of conduct.
The paper in Nature, published last June, promoted a technology called reinforcement learning, which the paper said could improve the design of computer chips. The technology was hailed as a breakthrough for artificial intelligence and a vast improvement on existing approaches to chip design. Google said it used this technique to develop its own chips for artificial intelligence computing.
Google has been applying the machine learning technique to chip design for years, and published a similar paper a year ago. Around that time, Google asked Dr. Chatterjee, who has a doctorate in computer science from the University of California, Berkeley, and has worked as a research scientist at Intel, to see if the approach could be sold or licensed to a chip design company, people familiar with the matter said General Chat Chat Lounge
But Dr. Chatterjee expressed reservations in an internal email about some of the paper’s claims and questioned whether the technology had been rigorously tested, three of the people said.
While the debate about that research continued, Google pitched another paper to Nature. For the submission, Google made some adjustments to the earlier paper and removed the names of the two authors, who worked closely with Dr. Chatterjee and had also expressed concerns about the paper’s main claims, the people said.
When the newer paper was published, some Google researchers were surprised. They believe it was not followed by a publishing approval process that Jeff Dean, the company’s senior vice president who oversees most of its AI efforts, said was necessary in the aftermath of Dr. Gebru’s firing, the people said.
Google and one of the paper’s two lead authors, Anna Goldie, who wrote it with a fellow computer scientist, Azalia Mirhoseini, said the changes made before the paper did not require a full approval process. Google allowed Dr. Chatterjee and a handful of internal and external investigators work on a paper that challenged some of its claims.
The team submitted a rebuttal paper to a so-called resolution committee for publication approval. Months later, the paper was rejected.
The researchers who worked on the rebuttal paper said they wanted to escalate the issue to Mr. Pichai and Alphabet’s board of directors. They argued that Google’s decision not to publish the rebuttal violated its own AI principles, including upholding high standards of scientific excellence. Soon after, Dr. Chatterjee was informed that he was no longer an employee, the people said.
Ms. Goldie said that Dr. Chatterjee had asked for their project in 2019 and that they had declined. When he later criticized it, she said, he could not substantiate his complaints and ignored the evidence they presented in response.
“Sat Chatterjee has waged a campaign against misinformation for me and Azalia for over two years now,” Ms. Goldie said in a written statement.
She said the work had been peer-reviewed by Nature, one of the most prestigious scientific publications. And she added that Google had used their methods to build new chips and that these chips were currently used in Google’s computer data centers.
Laurie M. Burgess, Dr. Chatterjee’s lawyer said it was disappointing that “certain authors of the nature paper are trying to shut down the scientific discussion by defaming and attacking Dr. Chatterjee for simply seeking scientific transparency. ” Ms. Burgess also questioned the leadership of Dr. Dean, who was one of the 20 co-authors of the nature paper.
“Jeff Dean’s actions to repress all relevant experimental data, not just data that supports his favorable hypothesis, should be deeply troubling both the scientific community and the broader community that consumes Google services and products,” Ms. Burgess said.
Dr. Dean did not respond to a request for comment.
After the rebuttal paper was shared with academics and other experts outside Google, the controversial spread spread across the global community of researchers who specialize in chip design.
The chip maker Nvidia says it has used methods for chip design that are similar to Google’s, but some experts are unsure what Google’s research means for the larger tech industry.
“If this is really working well, it would be a really great thing,” said Jens Lienig, a professor at the Dresden University of Technology in Germany, referring to the AI technology described in Google’s paper. “But it is not clear if it is working.”