  At future e+- e- linear colliders, the event rates and clean signals of
scalar fermion production - in particular for the scalar leptons - allow very
precise measurements of their masses and couplings and the determination of
their quantum numbers. Various methods are proposed for extracting these
parameters from the data at the sfermion thresholds and in the continuum. At
the same time, NLO radiative corrections and non-zero width effects have been
calculated in order to match the experimental accuracy. The substantial mixing
expected for the third generation sfermions opens up additional opportunities.
Techniques are presented for determining potential CP-violating phases and for
extracting tan(beta) from the stau sector, in particular at high values. The
consequences of possible large mass differences in the stop and sbottom system
are explored in dedicated analyses.
