Figure 2

Ad hoc retrieval runs sorted by MAP. This figure shows all of the runs (x-axis) sorted by MAP (y-axis). The highest run to obtain statistical significance (RMITa) from the top run (pllsgen4a2) is denoted, along with the "out of the box" TF*IDF run (OHSUNeeds) are annotated. (Only every fifth run identifier is shown to make the x-axis more readable.)