"In conclusion, most children do not learn or understand problems and ideals at the same rate. Children react differently to their surroundings and can perform better at certain tasks if that particular task involves something they can relate to, for example, the naughty teddy. This is a major disadvantage when using age as a marker for development as the child may be expected to act a certain way or produce different results than expected. Many of the criticisms of Piaget surround his underestimation of childhood capabilities and also the age at which the cognitive developments are said to take place. There are obviously many advantages to using the age as a marker for development, with reference to Piaget's stage theory. Many developmental psychologists use related age boundaries to discern the developing periods in a child's life. Also, many schools have revised their teaching approach and are now using Piagetian principles in the classroom. (Driscoll 1994). While possibly not wholly precise, Piaget's stage theory nonetheless provides a thorough explanation of the order in which Western children seem to develop and can be used by carers and teachers alike to aid their child's development throughout the different ages of its life."