[Insight-developers] When are variables made private vs protected?

[David Doria]

I am curious how the decision to make member variables private vs
protected is made. For example, I was trying to derive from
itkMedianImageFunction and I noticed that the member:

unsigned int m_NeighborhoodRadius;

is private. Therefore, in my subclass, I have to create a new
member+accessor+mutator for the same purpose. Why would all members in
ITK not be protected so that they can be more easily subclassed?

Thanks,

David