Informed consent refers to participants agreeing to their role in an experiment only after they have been adequately informed of all the risks and benefits that this activity involves. In order to avoid ethical problems, participants should only participate once they possess this information. Moreover, depending on the nature of the experiment, participants might have to go through a debriefing process afterwards to ensure that they were not damaged in any way by their participation.
The term dark ages is no longer in use because of the negative feedback it was given so we call itmiddle Ages instead and also more was known from the early middle ages so dark ages is okay for describing the middle ages.
