Factors that affected training techniques have included the recognition of law enforcement as a profession, concerns about liability, awareness that adults come to training with great experience and learn most effectively if involved in the training, and the availability of electronic and communications technology. Thus, although police academies still emphasize classroom lectures, at least half of a cadet's time is often spent in the field. Many trainers use simulators, particularly for firearms training and driving training, although some trainers do not support their use. Simulators should complement rather than replace traditional driver's training. Perhaps the most sophisticated and futuristic type of training uses virtual reality devices, although these are still extremely expensive for law enforcement. Regardless of the technology used, training programs now include topics relevant to current law enforcement issues, including techniques for gathering evidence for DNA profiling and compliance with the Americans with Disabilities Act. It is also important to recognize that even the most sophisticated technology cannot replace an effective instructor. Photograph