Subject or test subject (from the Latin probare " check " ) refers to a person who is undergoing an audit or is being investigated as a test subject.

In the literal sense, are subjects under test: imagine a test, they can exist or not, and are usually not anonymous: " The subject X with distinction. " The examination takes place in order to make a decision for each person.

The designation as a subject is generally and usually gender neutral used in the sciences that deal with people as individuals. In scientific studies subject refers to a subject (abbreviated VP, colloquial "guinea pigs "). She is subjected to a test or comparator example of a survey, medical examination, measurement, test or experiment. One subject is singled out as an individual element of a sample to check in a study specific research questions (hypotheses). The protection of subjects usually is subject to special conditions ( privacy, anonymity, ethical acceptability, health safety ). In medicine, and increasingly other areas Ethics Committees are responsible for assessing compliance with the rights of subjects.

In medical research subjects healthy participants in a clinical trial, in contrast to patients. As these subjects have signed a declaration of intent for clinical testing before participation and were included as subjects in the sample, such as a drug tester ". One subject became ill three days after his vaccination "

In the family history (genealogy ) and human genetics the person is referred to as Family, whose pedigree and family relationships are examined: " The proband is the daughter of X and Y and the mother of Z. " In contrast, preferred the ethnosociology the name of the person examined as ego, in order to clarify the reference point of the affinities.

In market research subject serves as a common gender-neutral term for a subject: " The respondent preferred brand X when buying detergents. "

In the rehabilitation of offenders, a person is referred to as Family, if the enforcement of their sentence or detention to probation, or if you for some other reason supervision of conduct occurs.