Pushing hands trains these technical principles in ever increasing complexity of patterns. At first students work basic patterns, then patterns with moving steps coordinated in different directions, patterns at differing heights (high, middle, low and combinations) and then finally different styles of "freestyle" push hands, which lead into sparring that combines closing and distancing strategies with long, medium and short range techniques. These exchanges are characterized as "question and answer" sessions between training partners; the person pushing is asking a question, the person receiving the push answers with their response. The answers should be "soft," without resistance or stiffness. The students hope to learn to not fight back when pushed nor retreat before anticipated force, but rather to allow the strength and direction of the push to determine their answer. The intent thereby is for the students to condition themselves and their reflexes to the point that they can meet an incoming force in softness, move with it until they determine its intent and then allow it to exhaust itself or redirect it into a harmless direction. The degree to which students maintain their balance while observing these requirements determines the appropriateness of their "answers." The expression used in some Tai Chi schools to describe this is "Give up oneself to follow another." The eventual goal for self-defense purposes is to achieve meeting the force, determining its direction and effectively redirecting it in as short a time as possible, with examples provided of seemingly instantaneous redirections at the highest levels of kung fu by traditional teachers. Pushing hands also teaches students safety habits in regard to their own vital areas, especially acupressure points, as well as introducing them to the principles of chin na and some aspects of the manipulative therapy or tui na also taught in traditional Tai Chi Chuan schools. At a certain point, pushing hands begins to take on aspects of "qigong (chi kung)", as the students learn to coordinate their movements in attack and defense with their breathing.