The Tang Dynasty adopted the personnel selection system and gradually refined it. The main subjects of the examinations were writing and study of classical books, which were the most popular. The prime ministers, named 'jinshi', were good at writing.
The candidates almost always came from two sources. These were students of official schools and also intelligent people in their local county, who were entitled 'juren' when they achieved the necessary qualifications to take the central government examinations held each spring.
The form and content of the exams varied from one another. The junior testing knowledge is in details, concentrating on small knowledge points. Therefore, the need to be able to recite the work was important. While the tests for 'jinshi' were not so easy - they required a talent for literature.
Candidates who passed the highest imperial examination held by the Board of Rites would have a promising future. The most successful scholar was then granted the title of 'zhuang yuan', the second 'bang yan', and the third 'tan hua'. However, there would be a final hurdle to cross - a test of another department 'the Board of Civil Office'. Then the tester will give those excellent people position according to their abilities. To become successful, candidates sometimes also needed the recommendation and instruction of a notable person with authority.
During the reign of Empress Wu Zetian, she asked questions of candidates herself in the imperial hall. This was the beginning of the interview examination. She also created the form of Wushu examination in subjects such as the use of fire arms.