Regular interview questions are asked. Just google some examples.
Answered - Payroll Specialist (Current Employee) - Halifax, NS
Stay focused, be preapred with examples of past experiences in other jobs that will help you getting your job done at ADP
Answered - Payroll Specialist (Former Employee) - Etobicoke, ON
Know your authoring tools - you will be tested on them.
Answered - Instructional Designer (Former Employee) - Islington and Bloor, Toronto, ON.
Mock cold call.
Answered - District Manager (Current Employee) - Mississauga, ON