A method for predicting local layout effect in a circuit design pattern includes obtaining a plurality of circuit design patterns, generating layout images from the circuit design patterns, extracting feature vectors from the layout images by processing the layout images in a computer vision machine learning algorithm, comparing the feature vector extracted from a selected layout image to clusters of feature vectors extracted from the layout images, wherein the clusters of feature vectors include an in-range cluster and an outlier cluster, and labelling a circuit design pattern corresponding to the selected layout image, for which threshold voltage has not been experimentally measured, as being an in-range circuit design pattern or an outlier circuit design pattern, in response to the selected layout image respectively correlating with the in-range cluster or with the outlier cluster.