Information Technology Reference
In-Depth Information
Ta b l e 2 .
Outcomes in the evening dress example
a.
Issues
b.
Interests
good
combi-
nation
jacket pants shirt
i
b
b
w
i
✗
j
b
b
r
j
✓
k
bww
k
✓
l
bwr
l
✗
m
wbw
m
✓
n
wbr
n
✗
o
www
o
✗
p
wwr
p
✓
j
j
i
k
m
k
m
j
p
l
n
i
k
m
i
p
l
n
p
l
n
o
o
o
(a) Preference graph induced by
CP-net.
(b.) Ceteris paribus ordering with
interests.
(c) Ceteris paribus ordering with
interests, good combination most
important.
Fig. 2.
Preference orderings (arrows point towards more preferred outcomes)
the employee. The relation between issues and interests does not have to be one-to-
one. There may be multiple issues that can satisfy an interest, some issues may satisfy
multiple interests at once, or a combination of issues may be needed to fulfill an interest.
As is common in defeasible reasoning, there may be exceptions to rules. For example,
one might say that a high position ensures status in general, but this effect is cancelled
out if the job is badly paid.
With the inference scheme of defeasible modus ponens (see scheme 1 in Table 4),
arguments can be constructed that derive statements about what interests are satisfied by
possible outcomes, based on their issue values and the rules relating issues to interests.
The conclusions from these arguments are summarized in Table 1b. If we compare the
possible outcomes ceteris paribus, we can construct a partial preference order for Mark,
with
b
and
d
being the most preferred options, and
g
the least preferred (see Figure 1a).
This preference order is not complete. To determine Mark's preference between
a
and
c
on the one hand and
f
on the other hand, we need to know whether wealth or family
time is more important to him. If wealth is more important, Mark will prefer
a
or
c
.
