One of the kinds of Knowledge disciplines is meta-composition, which is the understanding of theories behind spells and being able to reshape them. This is Julia's area in the 39 times she was at Brakebills.
They live in the attic above the library, although with much more luxury than one would think at first.
Quotes on KnowledgeEdit
Dean Fogg - "More than that. You... you understood the theory behind the spell and... and you reshaped it. Your discipline is meta-composition. You are a Knowledge student."
Julia - "Knowledge?"
Dean Fogg - "Part psychic, part physical. There really is no branch that it doesn't touch on. The short version: you are drawn, mind and body, to the discovery of magic."