If I recall correctly, the Native American archaeological exhibit at the
Ohio Historical Society museum in Columbus, Ohio, has an exhibit case
showing archaeologists in the field and another showing
?archaeologists/?designers preparing the exhibit? or otherwise working
in the museum itself.  I found them amusing, informative and
thought-provoking, but you would need to query the museum on their
measurement of success with them.
 
Also the [Boeing] Air Museum near Seattle has a wonderful exhibit about
designing the _planes_ and my memory suggests that this overlaps with
_designing the exhibits_ but that may just be my foggy memory, not the
reality.
 
The Canadian Museum of Civilization had projected an electric car to
follow a pre-set route through its vast storage areas--a kind of
"explanation of the museum"--but I don't know if that has in fact come
into being.
 
And I think it could be argued that virtually any kind of
"interactivity" by its nature incorporates some "behind-the-scenes"
presentation in addition to the exhibits "out front."
 
John
John Pearce
Center for Historic Preservation
Mary Washington College
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