Speakers and listeners using the same linguistic system exhibit
pervasive differences from one another.  The goal of this seminar is
to explore what this variability can tell us about the nature of the
linguistic system that the speakers share.  The specific topics to
be discussed will depend on the interests of students enrolled in
the seminar, but we expect to at least touch on simple person-to-
person variation (idiosyncratic variation within a population),
variation within a person due to context (such as due to register or
discourse setting), dialectal variation (such as due to geographic
locale), variation due to development and aging (including children
and the elderly), and variation due to different levels of
linguistic experience (including differences between native and non-
native speakers, and differences due to different kinds of
acquisition environments).