We've done a good deal of this charretting this year so far, and without the professors giving any explicit definition of the word, I've come to think of it as a quick, intense design process focusing on one aspect of the design. They've generally been pretty sketchy and conceptual to resolve an issue such as how the building responds to sunlight, or how the structure works with the composition. I've suspected, though, that's it a much broader term than how they've been using it with us. I've never thought of it as a final thing.