Training in process control environments requires operators to be prepared for temporal and adaptive transfer of skill. Three training methods were compared with regard to their effectiveness in supporting transfer: Drill & Practice (D&P), Error Training (ET), and procedure-based and error heuristics training (PHT). Communication electronics trainees (N = 61) were tested twice (9 and 13 weeks after training). The D&P group outperformed the ET group with respect to temporal transfer. The expected benefits of PHT and ET for adaptive transfer were not found. The superiority of D&P demonstrates that cognitive tasks also need repeated practice for temporal transfer. (Contains 4 tables and 5 figures.)