BRITTLENESS IN THE DESIGN OF COOPERATIVE PROBLEM-SOLVING SYSTEMS - THE EFFECTS ON USER PERFORMANCE

One of the critical problems in the design and use of advanced decisio n-support systems is their potential ''brittleness.'' This brittleness can arise because of the inability of the designer to anticipate and design for all of the scenarios that could arise during the use of the system, a deliberate decision by the designer to use an oversimplifie d model of the decision task (due to cost, time or technological limit ations), a failure of the designer to correctly anticipate the behavio r of the system in certain situations, or a failure to correctly imple ment the intended design, The typical ''safety valve'' to deal with th is problem is to keep a person ''in the loop'' requiring that person t o apply his or her expertise in making the final decision on what acti ons to take. This paper provides empirical data on how the role of the decision support system can have a major impact on the effectiveness of this design strategy. Using flight planning for commercial airlines as a testbed, three alternative designs for a graphical flight planni ng tool were evaluated, using 27 dispatchers and 30 pilots as subjects , The results show that the presentation of a suggestion or recommenda tion by the computer early in the person's own problem evaluation can have a significant impact on that person's decision processes, influen cing situation assessment and the evaluation of alternative solutions, If the scenario is one where the computer's brittleness leads to a po or recommendation, this impact can strongly influence tile person to m ake a poor decision.