Selection or training problem?

If one of our training programmes is not fully satisfactory, what steps should we take to put things right? Should we attempt to improve the quality of our training on the assumption that we have recruited the right trainees to the course? Or should we attempt to improve our procedures for recruiting and selecting trainees to the course on the assumption that our training is of a sufficiently high standard? In this article I shall be concerned to show how we can decide whether we have a selection or a training problem on our hands.