We draw on rich longitudinal data from one of the largest teacher education programs in Texas to examine the properties of rubric-based observational evaluations of preservice teachers (PSTs) during clinical teaching. Using a variance decomposition approach, we find that little of the variation in observation scores is attributable to actual differences between PSTs. Instead, differences in scores largely reflect differences in the rating standards of field supervisors. Men and PSTs of color receive systematically lower scores, as do PSTs in lower-income and rural placement schools. Finally, higher-scoring PSTs are slightly more likely to become employed as K-12 public school teachers and substantially more likely to be hired at the same school as their clinical teaching placement.