Logical Decisions - Classweb

Logical Decisions - Classweb Logical Decisions - Classweb

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MUF MUF Formula See also: Alternative Uncertainty Graph option, Level, Measure, MUF, Probabilistic Level, Sample, Simulation Options option, SUF, Trial, Uncertainty Summary option, Utility. A Multi-measure Utility Function (MUF) is the formula that combines the utilities for the individual measures computed by the SUFs into the utility for a goal. A MUF consists of two parts: a SUF for each measure and a set of scaling constants (called small ks) that determine the relative importance of the measures. (For goals with other goals as members, MUFs for the member goals may replace SUFs. The scaling constants are similar in both cases.) LDW uses two types of MUF Formulas to combine the measures -- an additive form where the small ks can be interpreted as weights and a multiplicative formula that includes an additional scaling constant called big K. Big K can be interpreted as the degree of interaction between the measures. See also: Alternative, Big K, Define Interactions option, Measure, MUF Formula, Small k, SUF, Tradeoff, Utility, Weight. LDW uses two formulas for MUFs. The additive formula is: U g(X) = k1U 1(X) + k2U 2(X) + ... + knU n(X), where U g(X)= is the utility of alternative X for the goal g, U i(X)= the utility of alternative X for the ith member of g, and k = the scaling constant small k for the ith member of g. i The additive formula requires that the small ks sum to 1.0 and that big K = 0.0. The additive formula is used as the default formula, when the Additive MUF option is selected and when big K is computed to equal 0.0. The second MUF formula is the multiplicative formula: U g(X) = ((1 + Kk1U 1(X))(1 + Kk2U 2(X))...(1 + KknU n(X)) - 1)/K, where g U (X) = the utility of alternative X for goal g, K= the scaling constant big K for g, 12-6 Section 12 -- Glossary

Nominal Utility Point Estimate k i= the scaling constant small k for member i of g, and U (X)= the utility of alternative X for member i i The multiplicative MUF formula is used when a non-additive option is selected in Define Interactions. The formula has three interesting limits -- If big K equals 0.0, the formula reduces to the additive formula. If big K equals -1.0, the formula reduces to U g(X) = (1 - U 1(X))(1 - U 2(X))...(1 - U n(X)) + 1, which equals 1.0 if U i(X) = 1.0 for any i. As big K gets very large, the formula becomes U g(X) = U 1(X)U 2(X)...U n(X), which equals 0.0 if U i(X) equals 0.0 for any i. Intermediate values of big K have intermediate degrees of interaction. Big Ks less than 0.0 mean that a high utility on an individual member can result in a high overall utility (constructive interaction), while big K greater than 0.0 indicates that a low utility on an individual member can result in a low overall utility (destructive interaction). See also: Additive MUF, Alternative, Big K, Define Interactions, Goal, Member, MUF, Small k, Utility. A nominal utility is assigned to all members of a goal when the utility is not directly specified. The nominal utility is assigned when the goal is defined and is generally set to 1.0, so that all members of the goal are assumed to have their most preferred levels if their level is not directly specified. This situation occurs while assessing tradeoffs, when a single measure is used to represent a goal in a tradeoff. When the tradeoff questions are displayed, the decision maker is asked to assume that the representative measure has a certain utility and that all other members of the goal have the nominal utility. See also: Goal, Measure, Member, Tradeoff, Utility. A point estimate for a measure level is a single number that will be the measure's level with certainty. This is in contrast to a probabilistic level, where a measure's level is not known with certainty and must be described with a probability distribution. See also: Level, Measure, Probabilistic Level. Section 12 -- Glossary 12-7

MUF<br />

MUF<br />

Formula<br />

See also: Alternative Uncertainty Graph option, Level, Measure,<br />

MUF, Probabilistic Level, Sample, Simulation Options option, SUF,<br />

Trial, Uncertainty Summary option, Utility.<br />

A Multi-measure Utility Function (MUF) is the formula that combines<br />

the utilities for the individual measures computed by the SUFs into<br />

the utility for a goal.<br />

A MUF consists of two parts: a SUF for each measure and a set of<br />

scaling constants (called small ks) that determine the relative<br />

importance of the measures. (For goals with other goals as members,<br />

MUFs for the member goals may replace SUFs. The scaling constants<br />

are similar in both cases.)<br />

LDW uses two types of MUF Formulas to combine the measures -- an<br />

additive form where the small ks can be interpreted as weights and a<br />

multiplicative formula that includes an additional scaling constant<br />

called big K. Big K can be interpreted as the degree of interaction<br />

between the measures.<br />

See also: Alternative, Big K, Define Interactions option, Measure,<br />

MUF Formula, Small k, SUF, Tradeoff, Utility, Weight.<br />

LDW uses two formulas for MUFs. The additive formula is:<br />

U g(X) = k1U 1(X) + k2U 2(X) + ... + knU n(X),<br />

where<br />

U g(X)=<br />

is the utility of alternative X for the goal g,<br />

U i(X)=<br />

the utility of alternative X for the ith member of g, and<br />

k = the scaling constant small k for the ith member of g.<br />

i<br />

The additive formula requires that the small ks sum to 1.0 and that<br />

big K = 0.0. The additive formula is used as the default formula,<br />

when the Additive MUF option is selected and when big K is<br />

computed to equal 0.0.<br />

The second MUF formula is the multiplicative formula:<br />

U g(X) = ((1 + Kk1U 1(X))(1 + Kk2U 2(X))...(1 + KknU n(X))<br />

- 1)/K,<br />

where<br />

g<br />

U (X) = the utility of alternative X for goal g,<br />

K= the scaling constant big K for g,<br />

12-6 Section 12 -- Glossary

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