Source:http://linkedlifedata.com/resource/umls/id/C1707957
NCI: A person who determines the significance, worth, or condition of something by careful appraisal and study.,NCI: The person, organization, or device making an observation. EXAMPLE(S): healthcare provider, adjudication committee, family member, radiologist, vendor (may provide a uniform assessment for all sites participating in a study), heart rate monitor, pace maker.