This color and gender sorting method made for at least one interesting observation: The heaviest users of portable telecommunications devices during the ceremony wore green robes. I noticed some blue-robes using these devices as well, but no white or black-robes. I was further away from the blue robed graduates, but could clearly see the female black and white robed students.
By observing frequency of use, I could also determine which speakers the graduates found most interesting. The principal's speech had the fewest number of users and the valedictorians' had the most.