well they send you a candidate handbook by e mail........one just has to go through it to have an idea of what CASS is all about?
basically its an assessment tool to measure the overall capability as a pilot.
which includes psychometry, mathematical skills, Perceptual Speed & Accuracy, English and speaking skill,reasoning skills like verbal, abstract and non verbal , , memory (short and long term), basic CRM skills, managing a lot of stress and a whole lot of different skills a good pilot should have. most of these skills are tested while flying on a simulator and thats where its gets difficult.
at the end of the day.. 375USD well spent ...no matter you pass or fail.