1. The formula of operant conditioning is R-S, which means behavioral response first, then stimulation. It is an operation behavior, and the case is Skinner's mouse pressing lever experiment. And the reaction behavior is to stimulate first, and then react. The formula is S-R, and the case is Pavlov's dog saliva secretion experiment.

2. In Piaget's cognitive development theory, the concept of conservation of children's acquisition is in the concrete operation stage, and children's thinking in the pre-operation stage is irreversible.

3. Observational learning was put forward by Bandura. She pays attention to examples and demonstrations, but its essence is an alternative reinforcement, not just examples or demonstrations.

Note: The answer is a little simple. 1 and 2 are incorrect, and 3 is not comprehensive.