Fig. 5

Subjective test results: a Test scores: when performed as the first test, the scores for Group B for Crowe’s classification III indicated poor performance, while the scores for Group B for Crowe’s classification IV indicated unqualified. RRA-SST can significantly improve the test scores for Crowe’s classifications II, III, and IV; b Number of errors: when performed as the first test, Group A made three errors while Group B made 16 errors; when performed as the second test, the number of errors in both two groups was greatly reduced