Intensive early intervention programs such as discrete trial teaching are intensive treatments designed to assist individuals with developmental disabilities, such as autism. This treatment involves teaching a variety of skills that individuals with disabilities may not pick up naturally. Programs often start by teaching pre-learning skills (sitting, attending, looking at trainer), social skills (looking at people, talking and interacting with them appropriately), safety skills (ability to state name, address, and phone number) and basic concepts (colors, letters, numbers). Individuals who are non-verbal may be taught to speak, use sign language, or use other communication devices. After these basics are mastered, higher-level skills are taught. This form of treatment works best when it begins in the pre-school years.