SP500215 Appendix B: System Features Appendix National Institute of Standards and Technology D. K. Harman liD. QUERY CONSTRUCTION--AUTOMMATICAILY BUILT QUERIES [OCRerr]OUTING) [OCRerr]11 non-stop terms were extracted from all known relevant docs for each query (disks 1 & 2). For cityri, the top 20 terms by the above selection criterion .[OCRerr]r cityr2, the same term pool and weights were used, but the number of terms varied between 3 and 31, based on the results of a long series of runs agai .[OCRerr]r cityri, a simple best match operator was used (doc weight = sum of term weights). Ek)r cityr2, the operator used was based on the results of experiments with the training set. For some queries, it was as for cityri, for others, as in Section