It has been discovered through experiments that using directed secants is the only technique that is correct for estimation of the degree of banding segregation covered in ASTM E1268, Standard Practice for Assessing the Degree of Banding or Orientation of Microstructures. Unfortunately, none of the criteria chosen in this standard can adequately characterize banding; therefore, it is described verbally. Anisotropy and the degree of orientation used in this standard characterize only the elongation of the separate features of the structure but cannot assess the tendency of these features (pearlite, bainite, carbides, and so on) to be combined into bands. Using the directed secants method, we have proposed a criterion that adequately estimates the degree of microstructural banding for a wide range of steels and alloys, including all the structures that are listed in Annex A1 of ASTM E1268. This criterion is the ratio of the standard deviation of the volume fraction of a “second phase” on the secants that are parallel to the deformation direction to the standard deviation of the volume fraction of a “second phase” on the secants that are perpendicular to the deformation direction. Considering that the banding according to the new criterion and the anisotropy according to ASTM E1268 are estimated by the same technique, the introduction of the new criterion to ASTM E1268 will be simple. A draft of these improvements has been developed and successfully balloted. Further improvement of ASTM E1268 can be attributed to the use of an image analyzer. Therefore, the principles of the standard practice for assessing the degree of banding or orientation of microstructures by automatic image analysis have been formulated.