subject; test subject; trial subject
Only when written 被験者
Refers to a person participating in a medical experiment, clinical trial, or psychological study. Often used in research contexts.
I participated as a subject in a clinical trial for a new drug.
Please prioritize the safety of the test subjects.
examinee; person undergoing an examination
Used for someone undergoing a medical examination, such as a full-body scan, health checkup, or diagnostic test. Less common than the first sense.
Examinees undergoing an MRI scan should remove any metal objects.
The university recruited test subjects for the clinical trial of a new drug.
The researcher administered a small dose of the drug to the test subject.
He participated in the experiment as a test subject.
モルモット is an informal, slightly humorous way to call someone a 'guinea pig' in an experiment, while 被験者 is the neutral, formal term used in research reports.
被験者 is counted with 人, the standard counter for people, as in 被験者10人.
Standard kanji form; used in news and formal contexts. The first sense is restricted to this spelling.
Alternate kanji form; less common but acceptable, especially for the second sense (examinee).
Compound of 被 (hi, 'receive') + 験 (ken, 'test') + 者 (sha, 'person'). The alternate form 被検者 uses 検 (ken, 'examine').