An experimental investigation of the relationship between decision makers, decision aids and decision making effort

This paper reports the results of two laboratory experiments designed to assess the impact of decision aid use on effort expenditures by decision makers. The traditional assumption in the decision support sytem (DSS) literature is that if decision makers are provided with expended processing capabilities they will use them to analyze problems in more depth and as a result make better decisions. Empirical studies investigating the relationship between DSS and decision quality have not borne this out. The explanation for such outcomes could be found in behavioral decision making theories. The literature on behavioral decision making indicates that the conservation of effort may be more important than increased decision quality in some cases. If this is so, then the use of a decision aid may result in effort savings but not improved decision performance. The two experiments reported here compare the information processing effort expended by users of a decision aid designed to support preferential choice problems to unaided decision makers. Effort is measured by deriving information use and processing measures from concurrent verbal protocols. The results support the concept of effort minimization. Total information use did not increase with the availability of the decision aid, rather the decision aid was used in such a way as to replace, rather than augment, decision maker effort. In the various aided conditions, the decision aid accounted for from 25-40% of the total information processed by the decision maker. The results further indicate that the impact of the decision aid is more pronounced in task settings with a larger number of alternatives to choose from. The implications of these results are discussed in the context of both DSS research and design.