The duplicate checking system will compare the English test paper to be detected with the English resources in the database and identify similar parts.
The duplicate checking system will compare the identified similar parts with the text of the whole paper and calculate the corresponding repetition rate.
Duplicate checking rate = (number of repeated words/total words) * 100%, in which, if 13 characters are similar continuously, it is judged as duplication, in other words, if it exceeds 13 words, it is marked as red in other systems, and the repetition rate is calculated.
In addition, some online tools and software can also provide more detailed repetition rate analysis, such as which parts are similar to other English resources given by paperfree, and provide corresponding quotations and reference materials. It should be noted that different duplicate checking systems may adopt different algorithms and rules when calculating the repetition rate, so different duplicate checking systems may produce different results.