Answer

Informed Consent: Some experiments wouldn’t work if participants knew the full aim.

E.g. – In Milgram’s study, if Participants knew that the study was about obedience, rather than learning and punishment, they would focus on obedience and their behaviour would be unnatural.

Deception: Sometimes it is necessary to deceive Participants in order to make an experiment work

E.g. – If the participants in Milgram’s study had known that the electric shock machine was fake, the task would not have worked. Obeying the authority figure would have been meaningless.

Protection from Physical and Mental Harm: Sometimes unintentionally harm is caused to participants.

E.g. – Milgram never expected Participants to obey the authority figure and administer strong electric shocks. Any harm was unexpected.

Right to withdraw: Reminding Participants of the right to withdraw may affect the validity of some experiments.

E.g. – Milgram could not remind the participants of the right to withdraw because his experiment was on obedience and the nature of the task was to encourage participants to continue to give electric shocks.

The experiment would not have worked if he had both urged them to continue and at the same time told them that they could withdraw from the experiment.