Assessor was a title given to Romulan officers who oversaw Reman slaves. On Romulus, the term "assessor" was a known euphemism. The Romulan Virron, a primary assessor, described the phrase thus: "In any other language it would mean what it is - slave driver. Overseer. Monster."
Assessors were qualified to allow certain Reman trustees to be trained in basic medical procedures related to mining accidents and childbirth. (TOS novel: Captain's Blood)