A person qualified to carry out assessment.
Source: UNEVOC/NCVER 2009, Global

A person that is able to conduct internal and external assessment for specific qualifications and/or part qualifications.
Source: SAQA 2013, South Africa

Accredited individual authorized to evaluate or assess competencies of a candidate (person) applying for certification.
Source: TESDA 2010, Philippines

An experienced and qualified professional who carries out the assessment, compares collected evidences with the performance standards / criteria of the job and then makes a formal assessment of the individual’s competence. The assessor formally records the result of the assessment and provides feedback to the individual. The line supervisor / manager normally conduct the first formal assessment of the individual’s competence. Other individuals that may be involved in the assessment process could include shift supervisors, shift controllers, job instructors or section heads. The most recognized assessment and verification methods, include some or all of the following:
•Testing (practical and / or written)
•Interview (individual and /or panel)
•Direct observation
•Examining work samples
•Evaluating reports produced by the individual
Source: Wahba 2013, Global