The Development of Chinese Poetry

What is poem? This question seems simple, but is hard to give a complete answer. Though some kinds of literature general courses giving definition to the poem, we can't use a fixed frame to measure all the works. For example, the explanation of poem in Cihai, it explained the poem: the poem needs to highly concentrate to summarize and reflect the social lives. It contains abundant thought, feeling and imagination. The refine language has a strong figurativeness. It also has some certain rhythm and usually organized in several lines. But there are some poem that we can see on the publication have none of these characteristic except organized in several poetry line. We can't tell whether it is a poem or not, and we could only say it isn't a good poem. Other people think that poem should be orderly and rhyming. But the Book of Family Names, One Thousand Character Primer and other relative verse, thought it has rhythm and organized in orderliness way. They are not poem. I am afraid we had to investigate from content to form comprehensively to judge whether it is a poem or not. And whether a poem is a good or a bad one, it is another question.