5. The method of claim 4 , wherein the user drill-down model comprises a conjunctive drill-down model.
5. The method of claim 4 , wherein the user drill-down model comprises a conjunctive drill-down model. 6. The method of claim 5 , wherein the conjunctive drill-down model comprises a model according to the function: U q M C ⁡ ( F q ) - E ⁡ [ X | q ] - E M C ⁡ [ X | q , F q ] - ∑ d ∈ q : r q ⁡ ( d ) > m ⁢ p ⁡ ( d - d q ) ⁢  D q , d , F q  .