Input-output relationships in on-line bibliographic searching

A methodology is proposed to aid in system design and evaluation of on-line bibliographic search systems. It uses multiple linear regression analysis to ascertain if there is a relationship between measures of search output (such as cost-effectiveness and cost) and input (such as the characteristics of the search—number of descriptors used, number of Boolean operators, charateristics of the requestor, and characteristics of the searcher). Four measures of cost-effectiveness and cost alone are presented and their values are calculated using empirical data from the DIALOG system for a sample of searches. From the sample data it is concluded that the costeffectiveness measures are not sensitive to input-variable changes. In contrast, there is a good statistical relation between the cost of an on-line search and the value of the input variables.