  In chalcogenide topological insulator materials, two types of
magneto-resistance (MR) effects are widely discussed: a positive MR dip around
zero magnetic field associated with the weak antilocalization (WAL) effect and
a linear MR effect which generally persists to high fields and high
temperatures. We have studied the MR of topological insulator Bi2Te3 films from
the metallic to semiconducting transport regime. While in metallic samples, the
WAL is difficult to identify due to the smallness of the WAL compared to the
samples' conductivity, the sharp WAL dip in the MR is clearly present in the
samples with higher resistivity. To correctly account for the low field MR by
the quantitative theory of WAL according to the Hikami-Larkin-Nagaoka (HLN)
model, we find that the classical (linear) MR effect should be separated from
the WAL quantum correction. Otherwise the WAL fitting alone yields an
unrealistically large coefficient $\alpha$ in the HLN analysis.
