Evaluate? Evaluate what? Training? What do we mean by training? What's to be evaluated? A particular training course? The trainees? The trainers? The training department? A certain set of training materials? Training in general?
More to the point, why evaluate it? Do we wish to gauge its effectiveness, that is, to see if it works? If so, what is it supposed to do? Change behavior? Shape attitudes? Improve job performance? Reduce defects? Increase sales? Enhance quality?

What about efficiency? How much time does the training consume? Can it be shortened? Can we make do with on-the-job training or can we completely eliminate training by substituting job aids instead?

What does it cost? Whatever it costs, is it worth it? Who says? On what basis? What are we trying to find out? For whom?

The preceding questions illustrate the complexity of any effort to evaluate training and emphasize the importance of being clear about the purposes of and the audiences for any such evaluation.