Mining Frequent Gradual Itemsets from Large Databases

Mining gradual rules plays a crucial role in many real world applications where huge volumes of complex numerical data must be handled, e.g., biological databases, survey databases, data streams or sensor readings. Gradual rules highlight complex order correlations of the form “The more/less X, then the more/less Y”. Such rules have been studied since the early 70’s, mostly in the fuzzy logic domain, where the main efforts have been focused on how to model and use such rules. However, mining gradual rules remains challenging because of the exponential combination space to explore. In this paper, we tackle the particular problem of handling huge volumes by proposing scalable methods. First, we formally define gradual association rules and we propose an original lattice-based approach. The GRITE algorithm is proposed for extracting gradual itemsets in an efficient manner. An experimental study on large-scale synthetic and real datasets is performed, showing the efficiency and interest of our approach.