>Hiya Nancy ---
>
>>I've following this thread all day, and I appreciate the lucid, substantive discussion.
>>
>>A couple of thoughts:
>>
>>"Coupling" one class to another by letting it refer by name to another class's property makes sense (I've found) in tightly related classes. So, it's a matter of degree and surely the literature should (if it doesn't) deal with degree of relationship. (I don't know the *right* words here.)
>>
>
>Ummm...I think static coupling and dynamic coupling.

IMO, object shouldn't access directly property/methods of objects of the same tier, but have to use property/methods of objects of upper tier to do this job.