Discuss the two major features of Piaget's formal operations stage

What will be an ideal response?

Piaget believed that at adolescence, young people become capable of hypothetico-deductive reasoning. When faced with a problem, they start with a hypothesis, or prediction about variables that might affect an outcome, from which they deduce logical, testable inferences. Then they systematically isolate and combine variables to see which of these inferences are confirmed in the real world. This form of problem solving begins with possibility and proceeds to reality.
A second important characteristic of Piaget's formal operational stage is propositional thought—adolescents' ability to evaluate the logic of propositions (verbal statements) without referring to real-world circumstances. In contrast, children can evaluate the logic of statements only by considering them against concrete evidence in the real world.
Although Piaget did not view language as playing a central role in cognitive development, he acknowledged its importance in adolescence. Formal operations require language-based and other symbolic systems that do not stand for real things, such as those in higher mathematics. Secondary school students use such systems in algebra and geometry. Formal operational thought also involves verbal reasoning about abstract concepts. Adolescents show that they can think in this way when they ponder the relations among time, space, and matter in physics or wonder about justice and freedom in philosophy.