  A critical analysis of three methods of estimating distances to cataclysmic
variables (CVs) is performed. These methods, by Ak et al., Beuermann, and
Knigge, all use near-infrared (JHK or Ks) magnitudes and the Barnes-Evans
relation. We compare all three methods to distances measured by trigonometric
parallax by Thorstensen, with Hubble Space Telescope, and with the HIPPARCOS
spacecraft.
  We find that the method of Ak et al. works best overall for all CVs,
predicting distances on the average 4% less than those measured by
trigonometric parallaxes. The method of Beuermann overestimates distances by
52%. The method of Knigge underestimates distances by 26%, although this was
only ever meant as a lower limit, since it assumes all light comes from the
secondary star.
