Which of the following is NOT one of Piaget's stages of cognitive development?

Piaget's theory of cognitive development is a well-respected framework that outlines the stages through which children progress as they develop their thinking abilities. These stages include the sensorimotor stage, the preoperational stage, the concrete operational stage, and the formal operational stage.

The correct choice, which identifies an option not included in Piaget's stages, is the term "Abstract operational." While the concept of abstract thinking is intrinsic to the formal operational stage, which is the stage where individuals begin to think logically about abstract concepts and hypothetical situations, there is no distinct stage known as abstract operational. This distinction is crucial in understanding Piaget's framework for cognitive development.

The other stages—preoperational, concrete operational, and formal operational—are all distinctly defined and represent specific periods in cognitive maturity during which children learn to conceptualize, reason, and understand the world around them in increasingly complex ways. Therefore, recognizing "Abstract operational" as an incorrect stage enhances the understanding of Piaget's theoretical model.