This story of Siri’s transformation, revealed for the first time here, might raise an eyebrow in much of the artificial intelligence world. Not that neural nets improved the system — of course they would do that — but that Apple was so quietly adept at doing it. Until recently, when Apple’s hiring in the AI field has stepped up and the company has made a few high-profile acquisitions, observers have viewed Apple as a laggard in what is shaping up as the most heated competition in the industry: the race to best use those powerful AI tools. Because Apple has always been so tight-lipped about what goes on behind badged doors, the AI cognoscenti didn’t know what Apple was up to in machine learning. “It’s not part of the community,” says Jerry Kaplan, who teaches a course at Stanford on the history of artificial intelligence. “Apple is the NSA of AI.” But AI’s Brahmins figured that if Apple’s efforts were as significant as Google’s or Facebook’s, they would have heard that.