Google Now voice search edges out Siri and Cortana in comparison

"Over the course of 3086 queries made by digital marketing consulting firm Stone Temple, Android's voice-activated search through Google Now returned 1795 results enhanced with custom content, while Siri on the iPhone served up 908 knowledge panels, and Windows Phone's Cortana gave 630. Knowledge panels are custom-built to answer specific types of questions, and do more than just shoot back web results.

Of those knowledge panels, Google Now search scored 88% accuracy for properly addressing questions, Siri came back right 53% of the time, and Cortana got 40%.

Those conducting the study pointed out that their focus was on knowledge panels, and not full digital assistant functions like adding calendar appointments or dictating e-mails. That said, don't take these results as providing a complete assessment of what your platform offers."