Not all master's theses of architecture in Southwest Jiaotong University need external review. Official website of Southwest Jiaotong University inquired that all master's theses of architecture should be evaluated blindly, and only those selected papers can participate in the external audit. The difference between the two is that they failed to pass the blind trial, and they can apply for blind trial again after revision. If you pass the blind trial, you can participate in the defense, but if you don't pass the external trial, you have a veto right and you can't participate in the defense of that year.