“…Queries in the dataset are, on average, 14 terms long, which is much shorter than the queries considered in this article (80 terms). After its introduction, the OHSUMED collection has been extensively used to evaluate classification (e.g., Genkin, Lewis, & Madigan, ; Han & Karypis, ; Xu & Li, ), learning to rank (e.g., Cao et al, ; Duh & Kirchhoff, ; Liu, Xu, Qin, Xiong, & Li, ), and query reformulation (Abdou & Savoy, ; Dong, Srimani, & Wang, ; Haveliwala, ; Hersh, Price, & Donohoe, ; Jalali & Borujerdi, ; Liu & Chu, ; Srinivasan, ; Thesprasith & Jaruskulchai, ). Works in the latter group are the most similar to our systems; they can be further partitioned based on the approach used: ontology‐based reformulation, Pseudo Relevance Feedback (PRF), and a combination of the two.…”