What is the term piaget used for the process in which one state is changed into another?

Transformation  is   the   term  used  by  Piaget  to  refer  for  the  process  in  which  one   state  is   changed  into   another.According to  Piaget  children  who  have  developed   concrete  operations  and  become   capable   of  combining,separating,ordering  and  transformating   objects   in  their  minds. According  to  Piaget, preoperational  children  do  not   readily  understand  how  thing   can  change  from  one  form  to  another.

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