I want to start a shade garden on the north side of my house--which I've just been assuming is in FULL shade. I'm always finding plants (catalogs, etc) that I WANT, but are labeled PART shade... Well, I recently read an article that claimed that areas like a north side of a building are in fact LESS than full shade (i.e. brighter) because the area is still "open to the sky"; it seemed to imply that it'd be considered PART shade...is it?!?
Unless there are shade trees nearby, the north side of a building can indeed be "part shade". At your latitude, in summer the sun rises in the northeast and sets in the northwest. That means that the north sides of buildings usually get a few hours of direct sun very early in the morning and/or late in the evening. As you note, there is also some "scattered sunlight" that strikes the area if the sky is open above it.