Which of the following is the most subjective method of educational psychology?

Concept: In educational psychology, a method for studying mental processes is judged "subjective" or "objective" by where its data comes from — data that only the individual's own private awareness can supply, with no independent observer able to confirm it, is subjective; data that an outside observer or a replicable procedure can also record is objective.

Application: Introspection asks a person to look inward and report their own thoughts, feelings, and sensations exactly as experienced from the first-person perspective. That report comes from nowhere but the individual's own private mind, so no second person can check it against anything external — which is exactly what makes it the most subjective of the methods listed here.

Cross-check — how the other three methods differ:

• Extrospection turns attention outward: it studies another person's expressed behaviour, which a second observer can also watch and compare notes on.

• Observation is carried out by a trained observer following a set protocol to record behaviour as it happens, so a different observer applying the same protocol can cross-check the record.

• Experimentation manipulates variables under controlled conditions and measures the resulting outcomes using a fixed, written procedure that any researcher can repeat and verify.

Because introspection alone yields data that only the reporting individual can access and verify, it is the most subjective method among these four.