Roxanne,

Good post!

(LOL..... I sat here in a "wow" daze so long staring at your opening that I almost forgot to read the rest of the post! Thank you Jim, you just made my day!)

It is true that inheritance is probably the single most overused feature of OO. While it is a necessary feature it is not the highest in terms of real reusability. One of the reasons for this is that inheritance requries a white box approach to class design. White box means that in order to specialize a class through subclassing it is necessary to now details about the the parent class's imlementation.

Boy that's exactly the the insight I was looking for with this Jim! And I believe you just showed me the bigger picture before I rounded the last bend in the road. :) I was seeing the benefits of favoring object composition over inheritance in regards to a partial reuse situation, but I hadn't connected that technique with the ideas of white box and black box implementations. Thanks so much Jim!!!!