Piper Jaffray analyst Gene Munster, who has regularly assessed Siri's accuracy in terms of correctly interpreting and answering queries, has issued the latest version of his Siri report card, noting that Siri has continued to improve under iOS 7, particularly in terms of being able to properly interpret questions being asked.
The primary improvement between Siri in iOS 6 and iOS 7 came from its performance in noisier areas, where Siri was able to translate better through a noisy environment (94% vs. 83% correct in Aug iOS 6). Based on our testing, iOS 7 Siri's net ability to answer questions (factors in questions not correctly understood) improved to 79% from 77% in August with iOS 6.
The improvements in Siri's understanding come alongside but separate from Apple's continued efforts to reduce its reliance on Google, as evidenced by Siri's shift to emphasize Bing, Wikipedia, and WolframAlpha results. In Munster's most recent testing, only 4 percent of Siri's answers relied on Google, compared to 17 percent in August testing and 27 percent in December 2012.
Munster also compares Siri to Google Now, finding that the two services are now essentially tied in effectiveness with a "C+" score after Siri held a substantial lead in the year-ago testing. In the latest testing, Google Now held small leads in content areas such as commerce and information, while Siri performed significantly better for operating system controls.
