The term means the three standards used to measure the truth of an assertion. The Chinese character biao (表) in this term means standard or norm. Mozi believed in judging right or wrong by following the three standards. The first one was the successful way in which the ancient sage kings had ruled. The second one was the actual experience of the people. The third one was whether one’s words and deeds actually served the interests of the state and people. Mozi established his school of thought on the basis of the three standards and used them to evaluate and criticize the doctrines of other schools.
To make assertions one must establish a standard of judgment. Speaking without a standard is analogous to trying to determine the time of sunrise and sunset on a revolving potter’s wheel. Distinctions of right and wrong, benefit and harm, cannot be clearly derived. Therefore, we must have the three standards. (Mozi)