Logical Decisions - Classweb

categories' sites. For example, the experts in the study said that
affecting ten "Processing Sites" would have about the same impact
as affecting just one "Residential Base with Interpretive Value."
Thus each processing site represented about one tenth the impact
of one site in the "currency" category and the "Processing Sites"
category was assigned a multiplier of 0.1.
To compute the measure level for each alternative, the number of
sites in each category was multiplied by its category multiplier
and summed.
The resulting measure level for each alternative could be
interpreted as the "equivalent" number of sites of the "currency"
category affected at each reservoir location. The units for the
prehistoric sites measure were thus defined as "equivalent
residential base sites with interpretive value."
The measure levels for particular alternatives were non-integer
numbers of residential base sites. A level of 2.5 on the prehistoric
sites measure means that the mix of sites in all the different
categories represents an impact halfway between two and three
residential base sites alone.
The advantage of combining the different types of prehistoric
sites in this way is that the preferences of higher level decision
makers can be assessed on a single simple but specific prehistoric
sites measure -- the number of residential base sites affected. In
addition, the level for each alternative reflects all of the various
types of prehistoric impact for that alternative.
See page 6-30 for a discussion of how to define and enter measure
category levels.
Quantifying Preferences
The most powerful and sophisticated parts of LDW are the
methods used to quantify preferences. LDW allows you to select
from several different methods to make the individual measures
comparable and to identify the relative importances of the
measures. These two steps are done separately and are discussed
separately in this section. The third preference assessment step -defining
multipliers for measure categories -- was discussed in the
previous section.
9-12 Section 9 -- In Depth