Stating the question another way, and posing the question to you...

You own a razor sharpening business, and give a pile of straights to a new employee to sharpen. (They don't even use straight razors.) You tell them how to sharpen the blades, and also tell them how to check the acceptability of the edge.

So, what did you tell them when you told them how to check the acceptability of the edge?

(I think the above thought experiment is a good one, for it aptly recreates the situation experienced by new users.)