Children during middle childhood (typically between the ages of 7-11) are limited in their cognitive abilities. Although they perform well when problems or questions are presented in concrete terms (i.e., shape, size, color), they perform poorly on tasks that require them to think beyond the concrete, processing at a more abstract level. Claudia would be classified in the concrete operational stage.

The other stages of Piaget's cognitive development theory are outlined below:

Sensorimotor stage (0-2 years): Children learn about their world through their explorations, using sensory and motor functions. 

Preoperational stage (2-6): Children begin to acquire language and represent symbols. 

Formal Operational stage (12+): Adolescents can engage in deductive and inductive reasoning. 

Adolescents think they have an imaginary audience when they believe that everyone is paying attention to them. 

Another limitation of their cognition is personal fable, meaning that they have this unrealistic opionion of themselves. 

Adolescents tend to engage in idealistic thinking, in which they ask "What if" questions, creating a utopia as opposed to a realistic view of the world. 

Propositional thought is actually a cognitive advance during adolescence. They are able to accurately evaluate given verbal statements and rules, without needing to refer to real-world truths or objects. 

The "visual cliff" experiments were designed to test the point in development at which young children acquire depth perception. Infants and toddlers were placed on a glass table with a gradient illusion, and experimenters observed whether they would cross the gradient. If the child crawled across the entire table, they demonstrated a lack of depth perception because they were unable to see (or be scared of) the visual cliff.

The stages of cognitive development, according to Jean Piaget, are the sensorimotor, preoperational, concrete operational, and formal operational stages. During the sensorimotor stage—birth through age two—the infant's knowledge is limited to their sensory perceptions and motor activities. Between the ages of two and six, when a child learns to use language, is the preoperational stage. Between the ages of seven and eleven, the child should gain an understanding of mental operations and begin to think logically. This is the concrete operational stage. From age twelve into adulthood, people will develop the ability to think about abstract concepts, and deductive reasoning will develop during the formal operational stage. 

In contrast to the behaviorist perspective of language acquisition championed by the like of B.F. Skinner, Chomsky argued that, because children can learn the rules of a language from incomplete evidence, that incomplete evidence must be supplemented by an innate linguistic capacity that all human beings are born with.

Piaget is known for his stages of cognitive development. These stages include: sensorimotor, preoperational, concrete operational and formal operational. With each stage, Piaget outlined a typical age range. For instance, the sensorimotor stage occurs in the first two years of life. During this stage, the child would experience the world through its actions and senses, which included: grasping, touching, looking, and the like. Although Piaget did believe children experienced egocentrism, he did not categorize it as its own stage. Instead, it is a developmental phenomenon of the preoperational stage. As a result, the choices egocentrism and object permanence are incorrect. The choices oral and id are stages in psychology; however, they are associated with Freud's psychoanalysis and are incorrect. 

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. During the first two years of life, a child will go through the sensorimotor stage where a child will experience the world through it senses (i.e. grasping and sight); therefore, object permanence occurs in the sensorimotor stage.

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. Preoperational stage occurs at the preschool age. At around 2 to 4 years of age, children Piaget theorized that children experience egocentrism. During this time, children have difficulty perceiving things from another's point of view. For example, a 3-year-old girl may cover her eyes with the intention of making herself invisible from her parents. As a result of her obstructed vision, she incorrectly assumes that her parents cannot see her.

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. At 2 to 7 years of age, Piaget believed that a child encounters the preoperational stage. At this point, a child is believed to be too young to preform mental operations (i.e. it is difficult for a child to imagine a situation and mentally reverse the action). This was observed in Sally's example. She decided that the narrow glass had more liquid despite the fact that both glasses contained the same amount of juice. In Sally's case, she demonstrates what Piaget thought as a lack of the concept of conservation. She cannot identify that despite the change in shape of the glass, the amount of juice is the same. 

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. At 6 to 11 years of age, Piaget believed that a child encounters the concrete operational stage. At this point, a child is believed to be old enough to grasp mathematical transformations and mental operations (i.e. they can imagine a situation and mentally reverse the action). This was observed in Kevin’s example. In Kevin’s case, he decided that both glasses contain equal quantities of juice. In this scenario, Kevin has a clear grasp of the concept of conservation, something that may not be true for a child in the preoperational stage.