IRS13 Evaluation Parameters chapter E. M. Keen Harvard University Gerard Salton Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. A ?urpos es 1. `Internal' test comparisons, "G1' constant. 2. 1External1 test comparisons, "G" varies. 3. Interpretation of merit in simulated real-life terms. 0 "-5 Viewpoints 1. System efficiency 2. User satisfaction Properties 1. Retrieval effectiveness alone 2. Independent of cut-off 3. Single number 4. Absolute and relative values 5. Differing user needs 6. Interpretation in users' terms 7. Comparisons involving "G11 changes Factors Affecting the Choice of Perfozi[OCRerr]ance Measures Figure 2.