Group Model: Experts

Yes, group of experts can work on the project !

ESTIMATION & CHOICE supports group decision making with a possibility to co-ordinate group of experts. Experts may be involved in finding coordinated weights for General Parameters, weights of Parameters influencing General Parameter, finding values of Utility Function for Qualitative Parameters. Experts may also compare alternatives on the final stage of the Benefit - Cost Analysis.

When you click button "Experts" you open list of experts working with current list of weight coefficients. For example if you click "Experts" on the page "General Parameters" you open list of experts, working on weight coefficients of General Parameters only. In other words, for every list of items with weight coefficients you may have separate list of experts.

Click "Add Expert" to add a new expert, and then input name of the new expert or select his name from the list of experts already working on this Plan of Analysis.

Click Experts' name to open list of items with weight coefficients assigned by this expert. To assign weights to the items expert can use either direct weighing or pairwise comparisons. If pairwise comparisons were used, the Consistency Index will be shown for this expert. If Consistency Index < 0.1 it means that expert was quite consistent in his answers. Please be advised that all experts working on the same list of items should use the same method of assigning the weight coefficients. If they do it directly, they should use the same scale, otherwise all experts should use parwise comparisons.

When all experts in group have assigned their weight coefficients you can calculate average weights and estimate experts' consistency. You can co-ordinate the opinions of up to 10 experts in the group. The system automatically checks first 10 experts in group to calculate there co-ordinated weights of the items and a Coefficient of Concordance. You also can manually check experts on the list to co-ordinate their decisions.

Just click button "Concordance" above the list of experts and you will get the average weights for the group of checked experts. It may look like:

Coefficient of Concordance: W=0.667

General Parameters	Average	Dispersion	Deviation
Economy	0.51	0.148	29.020
Safety	0.30	0.032	10.667
Driving	0.19	0.122	64.211

Coefficient of Concordance W reflects consistency of the experts: if W=0 than opinions of experts are contradictious, absolutely not co-ordinated. If W=1 opinions of experts about priorities (ranking) of items are absolutely co-ordinated.
It's a good idea try to achieve W not less than 0.7 .

Dispersion and Deviation show you the variance in experts' opinions on certain items. First of all you have to pay attention to the items with highest dispersion and deviation. You can discuss it with experts, may be some of them will change their mind about these discrepant items and then the Coefficient of Concordance will rise.

The system shows you as well an "Extravagancy Index" for experts. This coefficient indicates how far is the expert from the average ranking. The close Extravagancy Index to 1 - the more this expert's opinion contradicts the other experts. If all experts have the same order of items in their rankings, than Extravagancy Index equal 0 for every expert. If you want to increase the Coefficient of Concordance you should work with experts having highest Extravagancy Index (or even exclude such experts from concordance - if only they are not well-known specialists in the field!)

If you are content with results of co-ordination of experts' opinions - just click button 'Save coordinated weights...' , and the calculated average weights will be saved in the Plan of Analysis.

So, you have very powerful tools to improve co-ordination in the group of experts and get the reliable results.