Some applications, such as professional schools give applicants the choice to waive their right to view their letters or not. Usually, applicants are encouraged to waive their rights because if they do not, it is a sign they are not confident in their recommenders.
How important are letters of recommendation? Letters of recommendation are required for almost every graduate school application and are a very important part of the application process. Usually grades and test scores factor in most heavily; however, your letters of recommendation could be the deciding factor in the admission process.