What is a Carbon Copy?

In psychological measurements, copies are used to test test reliability. Test the same group of subjects with a copy similar to the master, and calculate the correlation between the scores obtained by the subjects in these two tests to determine the reliability of the test copy. An example of a common copy method is exam A and exam B. ^[1]

There are two main types:

It is usually understood as the ratio of the number of books (pieces) to the number of species, that is: the copy rate = the number of books (pieces) in the collection / the number of species in the collection. The rate of document duplication depends on the specific circumstances of the literature, such as teaching reference books in university libraries, and higher rates of popular reading in public libraries; duplicates for research and foreign language documents The capital ratio is lower, and there are no duplicates. ^[3]