Logical Decisions - Classweb

Overview of Preference Assessments
The purpose of the preference assessments is to collect the
judgments needed to combine the measure levels for an
alternative into an overall utility for that alternative. Three types
of preference judgments may be needed:
! Category Multipliers -- to allow measure category levels
to be combined into measure levels,
! Common Units Conversions -- to allow the measure
levels to be converted from their original units to
standardized units called utility, and
! Weight Assessments -- to allow the utilities for
individual measures and goals to be combined into
utilities for the higher level goals.
LDW gives you lots of freedom in the order and methods you use
for these assessments. In addition, LDW provides defaults so you
can skip steps and still do a ranking of your alternatives. LDW
lets you compute results based on your preference assessments at
any time.
Just before LDW displays the results, it computes the needed
ranking functions based on your preference assessments so far.
This computation is quite fast, so you probably won't even notice
when it is happening.
You should generally do the preference assessments in the order
of the options in the Assess menu. This will allow the most
detailed information to be aggregated first and will make the
results displayed in the weight assessment process more accurate.
Thus, we recommend that you assign the multipliers for any
measure categories first. Next, you should do the assessments for
the single measure utility functions that convert the measures to
common units. Finally, you should do the weight assessments.
Defining Category Multipliers
Measures with categories compute their level for an alternative as
the weighted sum of the alternative’s category levels. Thus,
Section 7 -- Using LDW 2: Assessing 7-5