the idea that some things can be ranked on a scale of moral value. For example, one might hold that human beings are more valuable than other sentient animals; sentient animals are more valuable than non-sentient animals, etc. Some defenders of animal experimentation argue that harming animals in research can be justified to benefit human beings because human beings are more valuable than animals.

a morally good or desirable character trait, such as honesty, courage, compassion, modesty, fairness, etc.

an ethical theory that emphasizes developing virtue as opposed to following rules or maximizing good/bad consequences.

the ability to make a free (un-coerced) choice. See Coercion, Informed consent.

a research subject who has an increased susceptibility to harm or exploitation due to his or her compromised ability to make decisions or advocate for his/her interests or his/her dependency. Vulnerability may be based on age, mental disability, institutionalization, language barriers, socioeconomic deprivation, or other factors. See Decision-making capacity, Informed consent.

 a person who reports suspected illegal or unethical activity, such as research misconduct or non-compliance with human subjects or animal regulations. Various laws and institutional policies protect whistleblowers from retaliation.

removing a human subjects research from a study. Subjects may voluntarily withdraw or be withdrawn by the researcher to protect them from harm or ensure the integrity of the study. Subjects who withdraw from a study may request to have their samples removed from the study (i.e. destroyed).