A system and method is described for evaluating a wafer fabrication process for forming patterns on a wafer based upon data. Multiple inspection regions are defined on the wafer for analysis. For each inspection region, images of patterns within the inspection region are captured, edges are detected, and lines are registered to lines of a reference pattern automatically generated from the design data. Line widths are determined from the edges. Measured line widths are analyzed to provide statistics and feedback information regarding the fabrication process. In particular embodiments defects are identified as where measured line widths lie outside boundaries determined from the statistics. In particular embodiments, lines of different drawn width and/or orientation are grouped and analyzed separately. Measured line widths may also be grouped for analysis according to geometry such as shape or proximity to other shapes in the inspection region to provide feedback for optical proximity correction rules.