Simply put, paper duplicate checking is to compare the papers submitted by the author with the database resources of the system itself, and finally the duplicate checking system automatically generates a duplicate checking report to obtain an overall similarity, which is what we often call the duplicate checking rate of papers. The judging rule is to calculate the repetition rate of the paper according to the criterion that 13 characters appear continuously and are judged as repetition.

The overall similarity is calculated by the ratio of the number of words similar to the database in the paper to the total number of words detected in the paper. The duplicate checking system first automatically cuts the submitted paper into paragraphs by line breaks; Then the sentences in the paragraph are extracted according to the punctuation marks in the paragraph; Finally, check the repetition sentence by sentence. At present, the duplicate checking system does not judge similar semantics as repetition, and its similarity is more about the comparison of words themselves, including keywords and their positions in sentences.

Paper duplicate checking includes text, original description, abstract, icon and formula description, references, appendices, experimental research results, conclusions, introduction, patents, documents, notes and various forms. During the graduation season, most colleges and universities will issue a notice explaining the specifications and duplicate checking instructions of the graduation thesis, and the school will uniformly issue the paper style and other contents, and generally explain the scope of duplicate checking in detail. If the school has specific requirements, it must be submitted according to the requirements of the school.