<Li> Number of times asking: Some argue that if a child is asked if the amount of liquid in the first set of glasses is equal then, after pouring the water into the taller glass, the experimenter asks again about the amount of liquid, the children will start to doubt their original answer . They may start to think that the original levels were not equal, which will influence their second answer . </Li> <Li> Word choice: The phrasing that the experimenter uses may affect how the child answers . If, in the liquid and glass example, the experimenter asks, "Which of these glasses has more liquid?", the child may think that his thoughts of them being the same is wrong because the adult is saying that one must have more . Alternatively, if the experimenter asks, "Are these equal?", then the child is more likely to say that they are, because the experimenter is implying that they are . </Li> <P> The final stage is known as the formal operational stage (adolescence and into adulthood, roughly ages 11 to approximately 15--20): Intelligence is demonstrated through the logical use of symbols related to abstract concepts . This form of thought includes "assumptions that have no necessary relation to reality ." At this point, the person is capable of hypothetical and deductive reasoning . During this time, people develop the ability to think about abstract concepts . </P> <P> Piaget stated that "hypothetico - deductive reasoning" becomes important during the formal operational stage . This type of thinking involves hypothetical "what - if" situations that are not always rooted in reality, i.e. counterfactual thinking . It is often required in science and mathematics . </P>

What is the piaget's stages of cognitive development