Explore the Cluster Variation Method (CVM) in this comprehensive lecture by Prof. Mike Widom. Delve into Kikuchi's method, which generalizes mean field theory for Ising models and alloys. Learn about CVM approximations to entropy and their applications in binary and high entropy alloys. Discover key concepts such as alternate spin representation, meanfield M, self-consistent condition, near neighbor pair energy, and Kikuchi's Method. Examine the ideal entropy, peculiar notation, and the inclusion-exclusion principle. Investigate the hierarchy of ordering, B32 structure, Monte Carlo methods, and convergence. Gain valuable insights into this advanced topic in materials science and statistical mechanics through this in-depth presentation.