Blind trial is relatively difficult. Issued by the school, mostly to other provinces, and the names and tutors' names are hidden. You don't know where your paper was sent, and the teachers there don't know where it came from and whose students it is, so the blind test is more objective and takes about one and a half months. Most external audits are issued by departments themselves. Although the names of students and tutors are also hidden, they are all sent to brother colleges with good relations in the province, so it is relatively less strict than blind audit. It will take about a month to a month and a half.

Extended data:

Blind evaluation refers to a system of organizing expert group evaluation, that is, anonymous submission, which means that the evaluation tutor does not know who the author of the paper is. In this way, the false positive rate of scores is low, which is generally used in college marking. The blind evaluation system is to send dissertations without the author's name to experts who can't know the author for evaluation, so the score should be the most objective. Colleges and universities in general, especially graduate schools, have relevant regulations on blind examination of papers on a regular basis, and most of them randomly select a certain number of papers for blind examination.

External auditing refers to sending papers to experts from other units for auditing. Some schools are managed by the degree office, while others are guided by tutors. 90% of the experts appointed by the tutor submit papers for review, and they can only pass because of the good relationship between the experts and the tutor.

References:

Baidu Encyclopedia-Blind Examination and External Examination