I applied online. The process took 3 days. I interviewed at Pearson (Grand Rapids, MI) in Feb 2016
Interview
There is a lengthy online application form; you must verify your education credentials. There are some training videos and quizzes that are easy. The actual determination of whether or not you'll be hired is made when you score practice sets. So you could go through all the online application, but end up not being hired if you can't pass the practice sets. You are paid for the training, however.
Interview questions [1]
Question 1
I was asked if I had teaching experience, and other scoring experience.