Pre-Post-Training Performance with Control Group Method The most sophisticated evaluative approach is the pre—post-training performance with control group method. Two groups are established and evaluated on actual job performance. Members of the control group work on the job but do not undergo instruction; the experimental group does receive instruction. At the conclusion of training, the two groups are reevaluated. If the training is really effective, the experimental group’s performance will not only have improved but will be substantially better than the control group. This approach attempts to correct for factors, other than the instruction program, that influence job performance.