Apple explains how it uses U.S. Census data and ML to make Siri a local

Based in part on data from the U.S. Census Bureau, Apple has been able to tune Siri to better understand users based on where they are and what POIs they're more likely to ask about. Apple says machine learning on its own has helped improve automatic speech recognition for general language over the years, but "recognizing named entities, like small local businesses" has proved a performance bottleneck. We decided to improve Siri's ability to recognize names of local POIs by incorporating knowledge of the user's location into our speech recognition system. That's done partly by relying on data collected by the U.S. Census Bureau: We define geo regions based on the combined statistical areas (CSAs) [1] from U.S. Census Bureau. The CSAs consist of adjacent metropolitan areas that are economically and socially linked, as measured by commuting patterns.