Recently, there has been significant interest in so-called Hybrid or Holistic Metrology, the practice of combining measurements from multiple sources in order to improve the estimation of one or more critical parameters. There also has been significant research in capturing and modeling the hierarchical spatial variability of CDs at the die, wafer, and lot level. However, the information inherent in spatial variability models has not been used towards improving the accuracy/precision of CD estimates. In this paper, we review the current trends in Hybrid Metrology and Spatial Variability Modeling, and provide a simple example based on the work of Zhang et al. 1 that illustrates how we can incorporate spatial information for improved measurement estimates.