Table 2.

Ablative study to understand the functionality of each module

Surgical instruction	B1	B2	B3	B4	C	M	R	S
LSTM	42.0	37.1	34.6	33.0	30.63	24.0	41.9	36.2
Soft-attn	44.6	39.7	37.1	35.5	32.79	24.8	44.9	38.9
Soft-attn + rl	44.9	39.7	37.3	35.4	33.06	24.8	45.2	39.3
Transformer only	52.4	48.0	45.5	43.8	41.32	29.9	52.8	46.7
Transformer + rl (ours)	56.1	52.2	49.8	48.2	45.61	32.7	56.6	50.9

B1, B2, B3, B4, C, M, R and S stand for 1–4 gram BLEU, CIDEr, METEOR, ROUGE-L and SPICE score, respectively