  We study half-twisted linear sigma models relevant to (0,2) compactifications
of the heterotic string. Focusing on theories with a (2,2) locus, we examine
the linear model parameter space and the dependence of genus zero half-twisted
correlators on these parameters. We show that in a class of theories the
correlators and parameters separate into A and B types, present techniques to
compute the dependence, and apply these to some examples. These results should
bear on the mathematics of (0,2) mirror symmetry and the physics of the moduli
space and Yukawa couplings in heterotic compactifications.
