ARGUMENTS FOR QUALITATIVE RISK ASSESSMENT - THE STAR RISK ADVISER

Calculating risk is relatively straightforward when there is reliable statistical evidence on which to base a judgment . However, novel tech nologies are often characterised by a lack of such historical data, wh ich creates a problem for risk assessment. In fact, numerical risk ass essment can be positively misleading in such situations. We describe a decision support system -- StAR -- that gives quantitative assessment s where appropriate, but which is also able to provide qualitative ris k assessments based on arguments for and against the presence of risk. The user is presented with a summary statement of risk, together with the arguments that underlie this assessment. Furthermore, the user is able to search beyond these top-level arguments in order to discover more about the available evidence. Here we suggest that this approach is well-suited to the way in which people naturally make decisions, an d we show how the StAR approach has been implemented in the domain of toxicological risk assessment.