  Since October 2010, the Chemistry-Biology Combined Major Program (CBCMP), an
international course taught in English at Osaka University, has been teaching
small classes (no more than 20 in size). We present data from the Force Concept
Inventory (FCI) given to first year classical mechanics students (N=47 students
over three years) pre and post score, for a class that predominantly uses
interactive engagement (IE), such as MasteringPhysics. Our findings show a
$G$-factor improved score of about $\sim$ 0.18, which is marginally about the
average of a traditional based course. Furthermore, we analyse in detail a set
of six questions from the FCI, involving the identification of forces acting on
a body. We find that student answers tend to cluster about "polarising
choices"-a pair of choices containing the correct choice and a wrong choice
with the latter corresponding to a superset of forces in the former. Our
results are suggestive that students have a good idea of the right set of
forces acting on a given system but the inclusion of extra force(s) brings
about confusion; something that may be explained by misleading ontological
categorisation of forces. In an appendix we also comment on possible
correlations between the pre/post score and the level of English ability on
entry to the course.
