Man-machine interaction and decision support systems: User modelling and dialogue specification

Decision support can be given in two quite different ways, either providing the user directly with the information he needs, or by providing him with assistance to find the information he needs. The former approach is traditionally applied in Computerized Operator Support Systems, information systems, and decision support systems. The second approach is to assist the operator in finding the information that is needed in each situation. This overcomes one limitation of the first approach, because it does not require a prior specification of a representative (not to say, exhaustive) set of situations. Instead it requires a specification of the general steps (or generic tasks) that the operator needs to carry out. This can on the most general level be done by referring to a standard decision model. But to be really useful, the decision-making must be seen in the context of the specific process and its characteristic demands, as provided e.g. by a cognitive task analysis. Based on this it is then possible to specify the typical dialogue sequences that are part of the decision-making. This can consequently be used to assist the operator in implementing the dialogue rather than implementing the specific steps (although this may later be added). User modelling in this approach refers to the operator as an active partner in the dialogue, rather than as a process supervisor or controller. The requirements to the Decision Support System will therefore be derived from the context of an overall dialogue, whose goal it is to bring about the decision, rather than from situation-specific requirements which may be mutually conflicting. This second approach works by structuring the situation rather than structuring the tasks. Even though the overall decision- making can be seen as composed of single tasks, the focus is on the organisation (and control) of these tasks rather than the tasks themselves. 11 refs, 4 figs