Uncertainty decision rule

Most probabilistic assessments have tended to combine variability and parameter uncertainty, and not consider model or decision rule uncertainty. Recent guidance from the US National Academy of Sciences (NRC 1994), USEPA (1997), US DOE (Bechtel Jacobs Company 1998), and others (Hattis and Burmaster 1994 Hoffman and Hammonds 1994) has emphasized the importance of tracking variability and parameter uncertainty separately. Indeed, the USEPA (2000) states that the risk assessor should strive to distinguish between variability and uncertainty. Two major advantages of tracking variability and parameter uncertainty separately in an uncertainty analysis are... 

This is not a restatement of the old observation that science is influenced diffusely and subtly by the prevailing value system of societv(22). It is to say that value-laden judgments are specific, readily identifiable and necessary parts of the cyclic sequence of activities that make up the scientific research method. Such judgments are the scientists means of coping with experimental uncertainty, i.e., the decision rules for testing statistical hypotheses (g.). ... 

A decision rule that describes how the measurement uncertainty wiii be taken into account with regard to accepting or rejecting a product according to its specification and the resuit of a measurement... 

Consider with stakeholders the uncertainties in risks, costs and benehts, and the consequences of false positives and false negatives when establishing decision rules. 

To resolve conflicts, decision makers must deal appropriately with uncertainty, conflicting objectives, or a lack of consensus. Conflict resolution, therefore, becomes a primary focus of decision theory. The following section presents an integrative model of decision making that relates conflict resolution to the above-discussed elements of decision making. This model specifically considers how decision making changes when different sources of conflict are present. It also matches methods of conflict resolution to particular sources of conflict and decision rules. 

Potential sources of conflict, methods of conflict resolution, and the results of conflict resolution are listed at the top of Figure 1. Each source of conflict maps to a particular method of conflict resolution, which then provides a result necessary to apply a decision rule, as schematically illustrated in the figure. Table 1 presents a set of decision rules, briefly describes their procedural nature and their required inputs, and also lists the sections of this chapter where they are covered. The required inputs of particular decision rules can be easily mapped to sources of conflict. As shown in the table, each decision rule requires that alternatives and their consequences be identified. Other decision rules require measures of aspiration, importance, preference, and uncertainty for each consequence or consequence dimension. For example, to compare alternatives using expected value, the probability and value of each consequence must also be known. Certeiin decision rules also accept inputs describing the degree of consensus between decision makers. 

Today s marketplace is characterised by turbulence and uncertainty. Market turbulence has tended to increase in recent years for a number of reasons. Demand in almost every industrial sector seems to be more volatile than was the case in the past. Product and technology life cycles have shortened significantly and competitive product introductions make life-cycle demand difficult to predict. Considerable chaos exists in our supply chains through the effects of such actions as sales promotions, quarterly sales incentives or decision rules such as reorder quantities. 

The precautionary principle purports to be a rule for decision making in uncertainty. In practice, however, it is quite the opposite a means of imposing arbitrary restrictions on the use of new technologies, be they products, processes, or services. 

Typically, a criterion is derived on the premise that the net transport effect should not alter the true chemical rate by more than some arbitrarily specified amount, normally 5%. Because of the uncertainty involved in knowing some of the necessary parameters, and since they are based on approximate rather than exact solutions, the philosophy of using the criteria should be conservative. As a general rule, a clear decision on whether a reaction takes place under kinetic or diffusion control is possible only when the calculated value of a criterion is significantly above or below the respective limiting value (i.e. an order of magnitude), otherwise a more detailed analysis is recommended. 

Temperature can alter not only the rate of vapor phase halogena-tions but also the nature of the products [rule (4), Section II, C, 2]. Previously the uncertainty was expressed as to whether kinetic or thermodynamic factors underlie this behavior. Others have assumed, without sound evidence, that kinetic factors are decisive and that the change in orientation signifies a switch in mechanism from electrophilic to radical character. However, further speculation on this point must await equally imaginative experimentation. 

In a properly constructed ranking analysis, each assumption has to be documented. A sensitivity analysis can be performed, investigating the impacts of ranking decisions upon the final outcome. Uncertainties can also be quantified and data gathered to make the ranking more based upon data-derived rules. 

In the assessment of the German NAP, the diverse uncertainties for the operators are again and again put forward as a central point of criticism and both clear and straightforward specifications are required, as well as long-term reliability. At the same time, diverse new special provisions are being demanded by many actors. The simplicity, transparency and calculability of the allocation rules, both for the operator and for the political decision-makers, should take on a special role with regard to future NAPs. 

All these uncertainties would be dispelled if clear evidence of extraterrestrial life could be obtained. Even then, kinship with earth life would have to be ruled out. Discovering life on Mars, for example, might not be decisive in itself. It is not considered impossible that Martian life could originate from earth, or terrestrial life from Mars, or both from some third site in the solar system. The two forms of life would have to differ in a significant way, for example in the chirality of some key constituent, for their independent origin to be incontrovertibly established. 

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