Unless I missed a link to a full shootout of the 4 systems, where are they getting the scores for each system in that comparison graphic in the inset? I ask be

Unless I missed a link to a full shootout of the 4 systems, where are they getting the scores for each system in that comparison graphic in the inset? I ask because Google clearly beat Siri on the specificity of the 3 answers shown, yet they scored Siri higher. I'd love to see a reasoning behind that.