Here's a Video that explains how the Google Survey team uses perceptual visual diffs (dpxdt) in their deployments: https://www.youtube.com/watch?v=UMnZiTL0tUc h

Here's a Video that explains how the Google Survey team uses perceptual visual diffs (dpxdt) in their deployments: https://www.youtube.com/watch?v=UMnZiTL0tUc https://www.youtube.com/watch?v=UMnZiTL0tUc