## 3 The Architecture of the NMT System
### B.4. B.4. B.5.
\begin{table}
\begin{tabular}{c c c c} \hline
**Test Set** & **Adequacy** & **Fluency** & **Overall Rating** \\ \hline Small test set & 3.1 & 3.0 & 3.1 \\ Medium test set & 3.3 & 3.1 & 3.2 \\ Large test set & 3.2 & 3.3 & 3.1 \\ \hline \end{tabular}
\end{table} 
Table 12: Human assessment of NMT model 4. \begin{table}
\begin{tabular}{c c c c} \hline
**Test Set** & **Adequacy** & **Fluency** & **Overall Rating** \\ \hline Small test set & 3.4 & 3.6 & 3.5 \\ Medium test set & 3.5 & 3.9 & 3.4 \\ Large test set & 3.2 & 3.8 & 3.3 \\ \hline \end{tabular}
\end{table} 
Table 13: BLEU score of the four NMT models. \begin{table}
\begin{tabular}{c c c c} \hline
**Test Set** & **Adequacy** & **Fluency** & **Overall Rating** \\ \hline Small test set & 13.12 & 13.39 & 14.11 & 15.45 \\ Medium test set & 38.01 & 37.23 & 39.01 & 43.23 \\ Large test set & 25.12 & 25.26 & 32.5 & 34.5 \\ \hline \end{tabular}
\end{table} 
Table 14: TER score of the four NMT models. \begin{table}
\begin{tabular}{c c c c} \hline
**Test Set** & **Adequacy** & **Fluency** & **Overall Rating** \\ \hline Small test set & 1.3 & 2.1 & 1.5 \\ Medium test set & 2.1 & 1.4 & 2.0 \\ Large test set & 1.9 & 1.7 & 1.6 \\ \hline \end{tabular}
\end{table} 
Table 10: Human assessment of NMT model 2. \begin{table}
\begin{tabular}{c c c c} \hline
**Test Set** & **Adequacy** & **Fluency** & **Overall Rating** \\ \hline Small test set & 2.6 & 3.5 & 2.8 \\ Medium test set & 2.5 & 3.6 & 2.4 \\ Large test set & 2.4 & 3.1 & 2.5 \\ \hline \end{tabular}
\end{table} 
Table 10: Human assessment of NMT model 3. \begin{table}
\begin{tabular}{c c c c} \hline
**Test Set** & **Adequacy** & **Fluency** & **Overall Rating** \\ \hline Small test set & 1.3 & 2.1 & 1.5 \\ Medium test set & 2.1 & 1.4 & 2.0 \\ Large test set & 1.9 & 1.7 & 1.6 \\ \hline \end{tabular}
\end{table} 
Table 10: Human assessment of NMT model 2. \begin{table}
\begin{tabular}{c c c c} \hline
**Test Set** & **Adequacy** & **Fluency** & **Overall Rating** \\ \hline Small test set & 2.6 & 3.5 & 2.8 \\ Medium test set & 2.5 & 3.6 & 2.4 \\ Large test set & 2.4 & 3.1 & 2.5 \\ \hline \end{tabular}
\end{table} 
Table 11: Human assessment of NMT model 3. #### 5.5.1 Analysis Based on Training Time

The amount of time required to train NMT models is contingent upon a variety of hyperparameters, including the number of hidden layers, the number of neurons present in each layer, the kind of encoder and decoder, the size of the training corpus, and many more. In order to train all four models, the number of neurons in each hidden layer was increased to 500, and the number of hidden layers was increased to four. The size of the training corpus varied amongst models, which increased the amount of time needed for training as the size of the corpus grew. Figure 5 shows the training time of each NMT model. NMT model 4 took the maximum time to train the model. #### 5.5.2 Analysis Based on the Test Set

The test set was segmented into three separate sets--small, medium, and large--so that the accuracy of the various NMT models may be evaluated [40,41]. Figures 6-8 show the BLEU and TER scores of the small, medium, and large test sets. By including the WE, MWEs, and named entities dataset, there was an increase in the BLEU score. The best BLEU score was obtained for NMT model 4. For the small test sample, the NMT model 4 received a 15.45 BLEU score, 43.32 for the medium test sample, and 34.5 for the large test sample. The NMT model 4 had the lowest TER score, so it is giving a better result than all four models, as also shown in Figures 6-8. #### 5.5.3 Analysis Based on Length of Sentence

The accuracy of the NMT model depends on the length of the sentence. To analyze this, ten sentences were randomly picked from a test set with different lengths. The BLEU score was calculated for these sentences individually for all NMT models. Figure 9 shows the BLEU score of the sentences. It is clear from the graph that as the sentence length increased after a certain value, the BLEU score started decreasing. Figure 5: The training time of the NMT models.