According to Jean Piaget's theory of cognitive development, what is the duration of the 'Pre-operational Stage'?

→ Which of the following psychological statements is most authentic and scientifically valid regarding the real psychological implications of 'Decentration'—a central concept under Jean Piaget's Theory of Cognitive Development defined as the advanced cognitive ability where a child can simultaneously consider, understand, and coordinate multiple aspects or dimensions of an object or situation rather than focusing on only one aspect, dimension, or feature (Centration)—and its scientific operation for students' multi-dimensional perspective, logical conservation, and cognitive flexibility in classroom teaching? → Under Jean Piaget's theory of cognitive development, when analyzing the capabilities of 'Hypothetico-Deductive Reasoning' and 'Combinatorial Thought' that develop in adolescents entering the 'Formal Operational Stage', which of the following statements most accurately defines the ontological and cognitive characteristics of this stage? → According to Piaget, in which stage of cognitive development does a child understand the concept of 'conservation'? → According to Jean Piaget's theory of cognitive development, what is the age range of the 'formal operational stage'? → According to Jean Piaget's theory of cognitive development, the quality of 'conservation' develops in which stage? → According to Jean Piaget, in which stage of cognitive development does a child learn the quality of 'conservation'? → According to Jean Piaget, the trait of 'Object Permanence' develops in which stage? → In the context of Jean Piaget's theory of cognitive development, consider the following statements: 1. According to Piaget, the concept of 'Conservation' develops primarily during the 'Pre-operational Stage', in which the child understands that even if the form or shape of an object changes, its quantity or mass remains unchanged. 2. The quality of 'Object Permanence' is a very important achievement of the 'Sensorimotor Stage', upon the development of which the child begins to understand that objects continue to exist even when they are out of sight. 3. The 'Formal Operational Stage' begins around 11-12 years of age, in which adolescents fully develop the capacity for 'Abstract Thinking' and 'Hypothetical-Deductive Reasoning'. 4. Piaget believed that children construct their knowledge actively by themselves, and the nature of their thinking differs from that of adults only quantitatively, not qualitatively. Which of the above statements are correct?