Full Idea
The 'scope' of a connective in a certain formula is the formulae linked by the connective, together with the connective itself and the (theoretically) encircling brackets
Clarification
'Theoretically' because logicians leave out brackets if they are unimportant
Gist of Idea
The 'scope' of a connective is the connective, the linked formulae, and the brackets
Source
E.J. Lemmon (Beginning Logic [1965], 2.1)
Book Reference
Lemmon,E.J.: 'Beginning Logic' [Nelson 1979], p.47