should always be aware that any evaluation, be it a formal appraisal
or informal opinion is never 100% accurate.
A number of factors of the object are evaluated and compared to similar features of
actual antiques, if not known, or if it is a well known item it is evaluated via experience/knowledge of the appraising/evaluating
With very good pictures a high accuracy may be possible, but sometimes it is necessary to look at the weight or sound/ring of an item, or the glaze bubbles and other minute details need to be viewed with a magnifier or microscope. If the evaluating person is unable to do this in person, that is if images are involved, this affects accuracy somewhat. In some cases the evaluation may be impossible.
With a supposedly valuable item always consider to get
two or more opinions or appraisals.
can be difficult to find knowledgeable "experts" or
"specialists" for many types of Chinese ceramics. This is also valid for those working in museums or major auction houses.
Many will have deeper knowledge only regarding some types of porcelain from the Ming (1368-1644) to the Qing dynasties (1644-1911), plus the republic period. With more than five hundred years and hundreds of kilns, it is virtually impossible to know all of it. Much more so if ages of 800 plus years are involved.
What is mostly known from any period concerns essentially items from mainstream kilns.
For example, with the Ming and Qing dynasties that would mainly be related to those items made in the ceramic metropolis of Jingdezhen, as well as Dehua kiln and Guangzhou (old name: Canton) which mainly made export wares.
Ceramics of much earlier periods appears to be more often seen now in the west. These are especially Yuan, Song/Jin, and Tang wares. Again, due to the presence of considerable numbers of kilns, those which at one time or another had been producing for the court, or were exported, etc. are better known, and they usually have a higher collecting value than others of the same period. (See Yuan/Song kiln systems.)
However, it is still clear that the latter, more ancient items are less known in the west than the former. This is not only the case with collectors, it appears also that even top auction houses often do not have access to experts whose specialty involves items from those earlier periods.
Naturally, this in turn means that ANY appraisal from these also may or may not be reliable. The "specialists" in the auction world appear to be told that they 'ARE' experts, unless they deny being one. But often "specialists" in this area of business are just that, business specialists. It is quite unlikely that you encounter one who has specialist knowledge in a very wide area of Chinese ceramics; often in the portfolio of auction houses these are also mentioned as "experts" for other Asian or Far Eastern ceramics, or Asian arts in general. They may not admit it, though, but business interests are dominant.
independent knowledgeable collectors or researchers may have much more
experience in a specific field, and may readily admit if they
don't know much about a subject. Unfortunately, often face-saving exercises prevent this. Simply said, even museum curators
may sometimes are not specialized enough on a certain type of
artifacts. Whichever it is, they may need to consult with others who are more specialized, but do they...?
If you need to ask for an appraisal, never rely on one only, obtain other opinions too if your knowledge regarding an object is insufficient.