Vygotsky placed much more emphasis on language than Piaget (book). Vygotsky's theory focuses on the role of interpersonal processes and the role of the child's community and culture that provide a structure from which the child's construction of meaning develops (book). Although Vygotsky emphasized that the process must take place in the context of the child's culture and the tools available within that culture. Vygotsky was always particularly interested in cognitive processes that underline understanding, which led to the concept of shared understanding that occurs when people communicate with each other. Vygotsky argued that through the use of language formed through social interaction a child can develop as a thinker and as a learner (book). As conscious individuals, people could not accomplish much without the aids and tools of their culture, such as language (book). Piaget argued that language was strongly influenced by underlying cognitive structures within the individual child (book). They also disagreed about the children's self-centered speech. By observing children, Piaget concluded that half of the errors made by children were due to egocentric speech which, according to him, showed that children did not try to communicate with another or did not adapt so that others could understand them, he also argued that young children did not seem to care whether anyone else might understand them and