Efficiently mining frequent embedded unordered trees

Mining frequent trees is very useful in domains like bioinformatics, web mining, mining semi-structured data, and so on. In this paper we introduce SLEUTH, an efficient algorithm for mining frequent, unordered, embedded subtrees in a database of labeled trees. The key contributions of our work are as follows: We give the first algorithm that enumerates all embedded, unordered trees. We propose a new equivalence class extension scheme to generate all candidate trees. We extend the notion of scope-list joins to compute frequency of unordered trees. We conduct performance evaluation on several synthetic and real datasets to show that SLEUTH is an efficient algorithm, which has performance comparable to TreeMiner, that mines only ordered trees.