Logical Decisions - Classweb

Storing your preference information
LDW stores your preference information in what are called
preference sets. When you start LDW it creates the first
preference set for you.
You can define many preference sets for a single decision
(perhaps for different people). You can add more preference sets
with the Edit::Add or View::Select/Change Preference Sets option.
Converting the Measures to Common Units
LDW converts an alternative's measure levels to common units
called utility before it combines them.
Each measure's most preferred level is assigned a utility of one
(1.0) while its least preferred level is assigned a utility of zero
(0.0). Intermediate levels are assigned with what is called a utility
function, or more specifically a SUF (for Single-measure Utility
Function).
The easiest conversion is a straight line, where each unit change
in a measure level results in an equal change in utility. This is the
most common case, and the default. (Defaults are the initial
settings used by LDW in various situations). So, if you want a
straight line conversion from a measure's original units to
utility you don't have to do anything.
Non-linear conversions
Sometimes a straight line SUFs isn’t right. Suppose you are hiring
employees and "years of experience" is one of your measures.
You might feel that after a certain point additional years of
experience aren't that helpful.
In this case you might think that the first few years of experience
add more utility than the last few. You can use a curved (“nonlinear”)
SUF to capture this idea.
In the example above, suppose two years experience is the least
preferred level and 30 years is the most preferred level, but that
you really want someone with around 5-10 years of experience.
In terms of desirability, you might end up defining the preference
mid-point of the 2-30 year range as five years. Figure 3-1 shows
the resulting curve for years of experience.
3-4 Section 3 -- Quick Start