According to the summary points, what are the three essential components of an experiment (RCT)?

The three essential components are manipulation, control, and randomization. Manipulation means the researcher gives an intervention to some participants, control involves introducing controls such as a comparison group that does not receive the intervention, and randomization means participants are assigned to conditions on a random basis.

As stated in the chapter, a true experimental or RCT design is characterized by three properties. Manipulation is the researcher doing something to at least some participants, typically by administering a treatment or intervention to one group and withholding it from another. Control means the researcher introduces controls over the research situation, usually by creating a counterfactual approximation such as a control group that does not receive the intervention. Randomization means the researcher assigns participants to either the experimental or control condition on a random basis. These three features together allow experiments to yield strong evidence about cause and effect by discrediting alternative explanations.