  The production of a charged lepton (e/mu) pair with a large missing energy at
a linear collider is discussed as a means of distinguishing the minimal
supersymmetry (MSSM) scenario from that with large extra dimensions (ADD) for
parameter ranges where the total cross sections are comparable for both.
Analyses in terms of event shape variables, specifically sphericity and thrust,
are shown to enable a clear discrimination in this regard.
