Balancing Tree Size and Accuracy in Fast Mining of Uncertain Frequent Patterns

To mine frequent patterns from uncertain data, many existing algorithms (e.g., UF-growth) directly calculate the expected support of a pattern. Consequently, they require a significant amount of storage space to capture all existential probability values among the items in the data. To reduce the amount of required storage space, some existing algorithms (e.g., PUF-growth) combine nodes with the same item by storing an upper bound on expected support. Consequently, they lead to many false positives in the intermediate mining step. There is trade-off between storage space and accuracy. In this paper, we introduce a new algorithm called MUF-growth for achieving a tighter upper bound on expected support than PUF-growth while balancing the storage space requirement. We evaluate the trade-off between storing more information to further tighten the bound and its effect on the performance of the algorithm. Our experimental results reveal a diminishing return on performance as the bound is increasingly tightened, allowing us to make a recommendation on the most effective use of extra storage towards increasing the efficiency of the algorithm.