The ability of conservation and seriation in the transition from the pre-operational stage to the stage of concrete logical operations

In the theoretical part of the thesis I closely addressed the Piaget's theory from the field of children's thinking. I described four stages of cognitive development as defined by Piaget. I focused on cognitive operations which are characteristic of the transition from the pre-operational stage to the stage of concrete logical operations, namely conservation and seriation. I summarized certain reviews of the Piaget's theory and described the use of the Piaget's theory in education. A part of the thesis was dedicated to science and scientific skills which had been in the empirical part of the thesis, and described constructivism and cognitive conflict as a learning strategy for beginner’s science. In the empirical part I presented the survey I conducted in kindergarten and in the 1st grade of primary school, between children aged from 5 years and 4 months to 7 years and 4 months. With a variety of tasks of the Piaget style, I considered whether participants have already developed capacity to solve the tasks of conservation and seriation, i.e. if they reached the stage of concrete logical operations. I wanted to know in particular, if the ages described by Piaget are valid today. Research results of observed sample of children have shown that 50 % of observed children successfully solve all tasks of conservation and seriation. The result of all tasks successfully solved and the results of successfully solved individual conservations tasks and the seriation task showed, that the age of the children, which successfully solve all of the above mentioned tasks is lower that the age, assumed by Piaget.