There are two interesting applications of association rules mining: one is multilevel and multidimensional association rules mining, while the other is constraint-based mining.
For a given transactional dataset, if there is a conceptual hierarchy that exists from some dimensions of the dataset, then we can apply multilevel association rules mining to this dataset. Any association rules mining algorithm applicable to the transaction dataset can be used for this task. The following table shows an example from the Amazon store:
TID |
Item purchased |
---|---|
1 |
Dell Venue 7 16 GB Tablet, HP Pavilion 17-e140us 17.3-Inch Laptop... |
2 |
Samsung Galaxy Tab 3 Lite, Razer Edge Pro 256GB Tablet… |
2 |
Acer C720P-2666 Chromebook, Logitech Wireless Combo MK270 with Keyboard and Mouse… |
2 |
Toshiba CB35-A3120 13.3-Inch Chromebook, Samsung Galaxy Tab 3 (7-Inch, White)… |
Have a look at the following flowchart that explains multilevel pattern mining:
Based on the conceptual hierarchy, lower-level concepts can be projected to higher-level concepts, and the new dataset with higher-level concepts can replace the original lower-level concepts.
The support counts are calculated at each conceptual level. Many A-Priori-like algorithms are designed with slightly different treatment to support count; here is a possible list of treatments available:
Constraint-based frequent pattern mining is a heuristic method with some user-specified constraints to prune the search space.
The ordinary constraints are, but not limited to, the following:
18.221.34.62