Jack is taking a class on piaget, and as part of an assignment he is "testing" some youngsters on various piagetian tasks. he gives 4-year-old meg a bag of red and blue marbles. they discuss the fact that marbles are made of glass. meg counts the marbles -- 7 reds and 18 blues. jack asks: "are there more blue marbles or more glass marbles? " meg says: "there are more blue marbles." this demonstrates meg's difficulty with

This demonstrates Meg's difficulty with "class inclusion".

Class inclusion alludes to the capacity to arrange objects into at least two classifications at the same time. For instance, the capacity to perceive that extensive classifications, for example, 'marbles' incorporates littler sub-classifications, for example, 'blue marbles' or 'red marbles' or distinctive colors. Piaget showed that youngsters in the pre-operational phase of scholarly improvement experienced issues noting questions like 'are there more blue marbles or more marbles?' because of their powerlessness to comprehend class inclusion.