The word skeptical was not meant as a criticism, nor did it refer only to the terms sensei, sempai kohai (although "sensei" is the subject of this thread). I think Chris is at times critical and skeptical about the Japanese ways, much in the same way as I am skeptical about the western ways of thinking. In itself I see this as a healthy attitude.
It is only that we differ of opinion; where he criticizes sempai - kohai structure there I see something worthwhile studying and applying. Also I think that it is not a structure that is alien to us; it is not much different from the hierarchical structure on board of ships, the kitchen of a restaurant or the fire-brigade. I have trained in several traditional kobudo dojo where this structure was in use without any problems. It is typically the members and instructors of Aikido dojo who have problems with it. . .
Best wishes from the Auvergne,
If I remember correctly, Peter has written a couple of posts about the sempai-kohei relationship here on Aikiweb. They are worth finding. If it wasnt Peter, my apologies. My memory is not always the best. Still, in areas like this, I would make sure that I was on very, very solid ground before debating either Peter or Chris. Just my opinion.