Paper duplication checking is to detect plagiarism or other academic misconduct by comparing the papers submitted by users with the documents in the duplication checking system. The duplicate checking system generally determines the similarity of texts by analyzing the language structure, semantic similarity and citation rules in the texts.

For your question, if you change a little every seven words, this way is likely to be detected by the duplicate checking system and counted as repetition. Because the duplicate checking system not only compares continuous characters, but also compares semantic and contextual information. If only a few words are simply modified without changing the structure and meaning of the whole sentence, then these modifications are likely to be regarded as invalid and cannot reduce the duplicate checking rate of the paper.

In addition, it should be noted that different duplicate checking systems and institutions may have different duplicate checking standards and requirements, so when checking papers, we should first understand the duplicate checking standards and requirements of our school or institution and choose an authoritative and reliable duplicate checking system for duplicate checking. At the same time, we should also pay attention to maintaining the accuracy and credibility of the literature, and we should not fabricate data or statements at will in order to reduce the repetition rate.