A discussion of ‘A selective review on calibration information from similar studies’

Being a long-time friend of Dr. Qin and served as a supervisor of Drs. Li and Liu, I am as proud as authors of the richness of the content as well as the broadness of this paper. It helps me to play catch up and shames me to work hard rather than hardly work. As a discussant, I wish to come up with some additional insight on this research topic but this is deemed a very difficult task. I should congratulate the authors for covering a vast territory and leave no room for that. Instead, I raise two not so important technical issues which might be of interest to some fellow researchers.