ISR10 Scientific Report No. ISR-10 Information Storage and Retrieval Evaluation of Document Retrieval Systems chapter Joseph John Rocchio Harvard University Gerard Salton Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. At this point, recall and precision functi&[OCRerr]s may be defined for the results of a retrieval operation with respect to a particular query. In particular, let the ranks of each member of the set of relevant documents D resulting from applying M to £q x be specified as: [OCRerr](i) for i = 0 where [OCRerr]i + 1) >[OCRerr]i). In this case: and ( 0 for 1 <x<[OCRerr]1) i rq(x) for n 0 I for x >0(n_)` (0 for 1[OCRerr]x[OCRerr][OCRerr]1) Pq(X) for [OCRerr](i) [OCRerr] x [OCRerr] [OCRerr]i+1) for x >[OCRerr]n_) At this point recall and precision error functions may be defined by the equations: recaU error $(r*'(x) - rq(x))[OCRerr]x (5.16) x=1 precision error = (5.17) f (p*(x) - Pq(X))dX x=1