UNDER SURVEILLANCE: Now that Coursera is offering "verified certificates" for $30 to $100 a pop, testing and cheating issues have really entered the fray. It's spawned a mini-industry for online proctors, and ProctorU is currently in talks to provide services for Coursera's millions of students. PBS takes a look at how the company verifies students and monitors them--and the computer screen--during the test-taking process. Each proctor handles only five students at a time, so one might wonder how ProctorU plans to scale. MOOC retention rates are pretty low right now, but once those smart folks figure out how to improve that, companies like ProctorU are just going to have to keep scaling...and scaling...