Cleverdon, Cyril W.2007-01-052007-01-051968-09http://hdl.handle.net/1826/1366Paper presented at The International Congress of the International Federation for Documentation, Moscow, September 1968The paper reviews one set of methods which can be used in the critical appraisal of various stages of an information retrieval system.3333401 bytesapplication/pdfenPresentation