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What is the Delta value in GAIA?
 
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Author: Bertrand Mareschal
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Votes: 3

 

Delta measures the quality of the GAIA representation. With respect to the total information contained in the decision problem (multicriteria table and preference functions) it is equal to the percentage of this information that is contained in the GAIA plane. Indeed some information is lost as the GAIA plane is limited to two dimensions (vs as many dimensions as the number of criteria in the multicriteria table).

As a rule of thumb, values larger than 70% can be considered as good: few information is lost and the GAIA plane provides a good and sufficiently reliable representation of the decision problem.

If the value of Delta is lower, the GAIA plane is less reliable and it should be analyzed very carefully. In such situations, partial analyses (including subsets of actions and/or criteria only) can be useful. An alternative is to use the 3D GAIA view provided by the PROMETHEE Software: the addition of a third dimension will increase the value of Delta.

Last update: 01:57 AM Monday, June 6, 2011

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