MONO91 Problems of Evaluation chapter Mary Elizabeth Stevens National Bureau of Standards less expensive than most other devices offering comparable speed of operation and search logic possibilities ii 1/ 2. 1'The experience of libraries that have gone through indexing using links and role indicators and careful edit:ing shows that indexing takes about one-half hour per document (or $4.00) and costs an additional $1.00 for routine processing." 2/ 3. In an investigation of the comparative merits of manual indexing of 2, 000 documents using the UDC classification system as against a KWIC index, Black gives the figure of approximately $1400 for the UDC case compared to about $600 for an in-house computer operation to produce KWIC listings, and somewhat more for a KWIC index compiled by a service bureau_3/ Time required to index, which directly involves cost is reported by Cleverdon to vary widely: "Few reliable figures have been given for current practices, although a particularly high figure is the 1 1/2 hours average quoted for indexing reports for the catalogue of aerodynamic data prepared by the Nationaal lluchtvaart laboratorium in Holland. It appears from personal discussions that an average of 20 minutes for a general collection of technical reports is the top limit, and this has been taken as the maximum indexing time to be used in the project." Insofar as such meagre data is indicative, there does not appear to be any particular cost-advantage for machine-compiled and machine-generated indexing other than the title- only KWIC indexes. Thus, Olmer and Rich report, in part: "The program ... lends itself to a variety of applications. One of these . .. is estimated to cost roughly $4.00 per document for cataloguing, putting on tape, printing and making any necessary corrections." 5/ This is for a case where the indexing (cataloging) is done manually. For a specific proposed automatic indexing system, employing a modified version of the Luhn word-frequency counting selection principle, Gallagher and Toomey report that: 1/ 2/ 3/ 4/ 5/ Linder, 1963 [361], p. 147. Lockheed Aircraft Corp., 1959 [369], p. 93. Black, 1962 [65], p. 318. Cleverdon. 1959 [126], p. 690. Olmer and Rich, 1963 [454], p. 182. 154