In a quantitative decision-analysis model, uncertainties are represented through probabilities -- specifically, subjective probabilities. The decision maker's attitude to risk is represented by utility functions, and the attitude to trade-offs between conflicting objectives can be expressed using multi-attribute value functions or multi-attribute utility functions (if there is risk involved). (In some cases, utility functions can be replaced by the probability of achieving an uncertain aspiration level or "target".) Based on the axioms of decision analysis, the best decision to choose is the one whose consequences have the maximum expected utility (or that maximizes the probability of achieving the uncertain aspiration level).