Logical Decisions - Classweb

Probabilities
There is a problem with the numbers in the Fuel Economy
column. The numbers are the sum of the two category numbers,
not the average.
To get the proper numbers you must change the category
multipliers. They are the numbers at the top of the column for
each category. (Did you notice that LDW added this row when
you created the first category?) LDW computes the measure
levels by multiplying each category level by the category's
multiplier and then summing the adjusted levels.
Initially, LDW sets each new category multiplier to 1.0. To get the
average of the two categories, we need to set each category's
multiplier to ½ (0.5). To do this:
1. Type in 0.5 in the cell for each category multiplier.
You should now see the proper averages in the cells for the "Fuel
Economy" measure.
The category multipliers are preference judgements. For
example, a buyer that does 80% city driving might want to use
multipliers of 0.8 for "City" and 0.2 for "Highway". For this
reason, each preference set has its own set of multipliers. You
could use this feature to see the effects on the overall ranking of
different multipliers for the two mileage categories.
LDW lets you define levels as probability distributions. With this
ability you can see how uncertainties in the levels might influence
the desirability of the alternatives.
To see how LDW uses probabilities, we will add a new measure
called “Resale Value” to the truck analysis. The units for "Resale
Value" will be the percent of the original price we would be able
to get if we resold the truck after five years.
Since we don't know what we will be able to get when we sell the
car, we will use probability distributions as the levels for "Resale
Value."
Section 5 -- Advanced Tutorial 5-3