METEOR = (1 − p) ×

P R

,

αP + (1 − α)R
m )θ, ch is the number of chunks, which means a

(2)

CIDEr stands for consensus-based image description evaluation. let c be a candidate caption, S be a set of
reference captions, and CIDEr is obtained by averaging the similarity of different lengths:

28

CIDErn(c, S) = 1

M

gn(c) × gn(Si)

||gn(c)|| × ||gn(Si)|| ,

MX

i=1

(3)

where M denotes the number of reference captions and gn(·) denotes an n-gram-based TF-IDF vector.

E Detailed Experimental Outputs
BiomedGPT