  A resolving set for a graph $\Gamma$ is a collection of vertices $S$, chosen
so that for each vertex $v$, the list of distances from $v$ to the members of
$S$ uniquely specifies $v$. The metric dimension of $\Gamma$ is the smallest
size of a resolving set for $\Gamma$. Much attention has been paid to the
metric dimension of distance-regular graphs. Work of Babai from the early 1980s
yields general bounds on the metric dimension of primitive distance-regular
graphs in terms of their parameters. We show how the metric dimension of an
imprimitive distance-regular graph can be related to that of its halved and
folded graphs, but also consider infinite families (including Taylor graphs and
the incidence graphs of certain symmetric designs) where more precise results
are possible.
