Comparative costs of manual and on-line bibliographic searching

A review of published studies reveals that the cost of comparable manual and on-line searches are approximately equal. The cost of on-line searching has decreased during the last decade mainly because of diminished data processing and telecommunications charges. There are some indications that expected future reductions in these cost components may be, to some extent, offset by increasing data base royalty charges. The relative effectiveness of manual and on-line search in terms of performance measures (e.g. recall and pre cision) seems to depend on a number of factors which include specificity of search and the nature of the data base.