# Think Twice: A Post-Processing Approach for the Chinese Spelling Error Correction
## 5 Experiments
### Results
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Character Level**} & \multicolumn{6}{c}{**Sentence Level**} \\ \hline \multicolumn{13}{c}{**Detection**} & \multicolumn{6}{c}{**Correction**} & \multicolumn{6}{c}{**Detection**} & \multicolumn{6}{c}{**Correction**} \\ \hline SIGHAN13 & D-P & D-R & D-F & C-P & C-R & C-F & D-P & D-R & D-F & FPR & C-P & C-R & C-F & FPR \\ \hline BERT & 83.3 & **90.7** & 86.9 & 81.6 & 88.8 & 85.0 & 77.0 & 73.1 & 75.0 & (-) & 74.8 & 71.1 & 72.9 & (-) \\ SpellGCN & 84.6 & **89.6** & 87.0 & 83.6 & **88.5** & 86.0 & 78.6 & 73.7 & 76.1 & (-) & 77.3 & 72.5 & 74.8 & (-) \\ BERT-FP & 83.7 & 90.5 & 87.0 & 82.1 & **88.9** & 85.3 & 74.4 & 73.5 & 75.4 & (-) & 75.3 & 75.1 & 75.3 & (-) \\ SpellGCN-FP & 84.8 & 89.1 & 86.9 & 83.9 & 88.2 & 86.0 & 78.4 & 73.1 & 75.7 & (-) & 77.4 & 72.1 & 74.6 & (-) \\ \hline
**BERT-PoP** & **92.4** & 82.8 & **87.4** & **90.5** & 81.1 & **85.5** & **83.9** & **73.5** & **78.4** & (-) & **81.7** & **71.5** & **76.2** & (-) \\
**SpellGCN-PoP** & **91.7** & 85.6 & **88.6** & **90.5** & 84.5 & **87.4** & **84.4** & **76.1** & **80.0** & (-) & **83.1** & **74.9** & **78.8** & (-) \\ \hline SIGHAN14 & D-P & D-R & D-F & C-P & C-R & C-F & D-P & D-R & D-F & FPR & C-P & C-R & C-F & FPR \\ \hline BERT & 78.6 & **79.3** & **78.9** & 76.6 & **77.4** & 77.0 & 66.7 & **69.8** & 68.1 & 25.9 & 65.0 & **68.0** & 66.4 & 26.8 \\ SpellGCN & 79.4 & **77.1** & **78.3** & 77.9 & 75.7 & 76.8 & 65.8 & 68.3 & 67.0 & 26.2 & 64.7 & 67.3 & 66.0 & 26.1 \\ Bert-FP & 78.6 & 78.6 & 78.6 & 77.4 & **77.4** & **77.4** & 67.0 & 69.4 & **68.2** & 25.5 & 65.6 & **68.0** & **66.8** & 26.2 \\ SpellGCN-FP & 79.7 & 76.6 & 78.2 & 78.7 & **75.7** & **77.2** & 66.1 & **68.7** & **67.3** & 26.1 & 65.4 & **68.0** & **66.7** & 26.4 \\ \hline
**BERT-PoP** & **86.3** & 64.2 & 73.6 & **83.7** & 62.3 & 71.4 & **68.1** & 56.9 & 62.0 & **21.1** & **66.0** & 55.2 & 60.0 & **22.2** \\
**SpellGCN-PoP** & **84.7** & 67.4 & 75.1 & **83.5** & 66.4 & 74 & **66.8** & 60.1 & 63.3 & **23.0** & **66.0** & 59.4 & 62.5 & **23.4** \\ \hline SIGHAN15 & D-P & D-R & D-F & C-P & C-R & C-F & D-P & D-R & D-F & FPR & C-P & C-R & C-F & FPR \\ \hline BERT & 78.6 & **80.2** & **79.4** & 74.6 & **76.1** & 75.4 & 67.3 & **70.5** & **68.9** & 25.5 & 64.4 & **67.5** & 65.9 & 27.2 \\ SpellGCN & 79.1 & **80** & **79.4** & 75.1 & **75.6** & **75.3** & 67.9 & **72.6** & 70.2 & 25.5 & 65.4 & **70.0** & 67.5 & 27.0 \\ Bert-FP & 79.1 & 79.7 & **79.4** & 75.6 & **76.1** & **75.9** & 67.1 & 70.0 & 68.5 & 25.5 & 64.8 & **67.5** & **66.1** & 26.8 \\ SpellGCN-FP & 79.0 & 79.2 & 79.1 & 75.2 & 75.4 & **75.3** & 67.8 & 72.3 & 70.0 & 25.5 & 65.6 & 69.9 & **67.7** & 26.8 \\ \hline
**BERT-PoP** & **87.0** & 70.0 & 77.3 & **81.9** & 65.5 & 72.8 & **71.8** & 63.7 & 67.5 & **20.0** & **68.7** & 61.0 & 64.6 & **21.7** \\
**SpellGCN-PoP** & **84.8** & 73.4 & 78.6 & **80.1** & 69.3 & 74.2 & **71.2** & 67.8 & 69.5 & **21.5** & **68.0** & 64.7 & 66.3 & **23.4** \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The test results after the post-processing operation on the two basic models. We recorded detailed different test indicators of two different subtasks: error detection and error correction on the test set in terms of character level and sentence level. P, R, F represent Precision, Recall, and F1 score. In the sentence level test, we also introduced the False Positive Rate (FPR). We intensified the improved results compared to the original model after introducing post-processing operation as an experimental comparison. FP denotes filter by probability, and PoP denotes post-processing. on precision and recall were balanced, so the F1 score was basically unchanged at the sentence level. The post-processing operation can significantly reduce the model's False Positive Rate (FPR). FPR measures the unnecessary correction of the model, which is also the current algorithm's limitation in the actual error correction application. The FPR values of the two models descended by 3 % to 6%.