An appraisal can simply be defined as an opinion of value. If you showed a picture of an item to five different people, you would probably get five opinions of its value.
An appraiser is a person with an informed opinion. In addition to having general knowledge of materials and usually a few areas of specialization, an appraiser is one who studies the media in detail, identifies them, judges the aspects of their condition and value and then communicates the findings ethically in an appraisal document. The appraiser will identify and value all the objects for which the appraiser’s training, experience and accreditation qualify him or her, and will refer to or consult other specialists as required.
In addition to having the willingness to spend time on research, they have a high level of integrity and MOST IMPORTANTLY adhere to a strict code of ethics at all times.