The linear absorption and fluorescence spectra as well as the oscillator strengyths of 2,2',7,7'-tetraphenyl-9,9'-spirobifluorene (A), 2,2',7,7'-tetrakis(biphenyl-4-yl)-9,9'-spirobiflourene (B), and 2,2',7,7'-tetrakis(9,9'-spirobifluorene-2-yl)-9,9'-spirobifluorene (C) are calculated oil the basis of the collective electronic oscillator (CEO) approach of Mukamel et al. (see, e.g., Chein. Rev. 2002, 102, 3 17 1). The graphical visualization and quantitative characterization of CEO modes allows one to extract the real-space distribution of electronic excitations of the molecules Under Study. Effects of the lengthening and branching of the oligophenylene segments have been analyzed. The influence of the lowest excited (S-1) vs ground-state (S-0) geometry changes on the CEO modes is investigated and related to the geometry changes of: the molecular parts. The obtained theoretical results are in good agreement with experimental trends observed in absorption and fluorescence data.