We presented two new algorithms, Apriori and AprioriTid, for discovering all signicant association
rules between items in a large database of transactions. We compared these algorithms to
the previously known algorithms, the AIS [AIS93b] and SETM [HS93] algorithms. We presented
experimental results, using both synthetic and real-life data, showing that the proposed algorithms
always outperform AIS and SETM. The performance gap increased with the problem size, and
ranged from a factor of three for small problems to more than an order of magnitude for large
problems.