Nick Hall submitted this practical exercise to be included in an interview when recruiting a new trainer.

I have used this many times and it gives you a good feel for a new trainers potential without putting too much strain on the individual.

Write and deliver an introduction to a training course using the INTRO structure (no need to acually write or deliver the course itself). Choose any subject you want.

I= Introduction/Interest: Introduce yourself and the course. Give the course an interesting and thought provoking title. For instance I call my presentation skills course 'Feel the Fear'.
N= Need: Explain why this course is necessary for these particular people. How it fits into the bigger picture of their role.
T= Timings: How long is the course? When are the breaks?
R=Range: What does the course cover? What does it not cover? For instance my presentation skills course covers good use of PowerPoint, but does NOT teach you how to use it.
O= Objectives: What are the learning objectives of the course?

This should not take too long to prepare and will definitely give you a flavour of how your new trainers approach the art of training.