Game Development Reference
In-Depth Information
Everything there involves concrete counts and figures. “The number of…� is a
very safe and comfortable place for computers (and their programmers).
As we discussed earlier in the topic, concrete counts and measurements don't
necessarily correspond equally to
utility
. Therefore, when dealing with these types
of items, we need to determine which of the two values we are going to measure. In
Chapter 8, we discussed numerous examples where we were building armies. The
number of soldiers we had already built was a criterion in the decision. More im-
portantly, however, we were measuring the marginal utility of building additional
soldiers. The abstract concept of utility is different from the concrete count that we
started with.
If we are using the raw number or value of an object in a calculation, there is lit-
tle that we need to consider with regard to how we are weighting it as a decision cri-
terion. However, when switching to utility, we have some subjective judgments to
make. As such, the range and granularity that we select for our scale will be largely
context-dependant.
In this topic so far, we have covered many different examples that we would
treat in a variety of manners. Even going back to my razor blades in Chapter 2, we
could devise a way of scoring my relative satisfaction with the blades. We may use
the number of uses as a starting point, but my satisfaction with a blade is not as lin-
ear as counting the times I have used it. For example, we could state that a blade
starts with a quality of 100 when it is brand new, but, as I use it, its quality decreases
rapidly at first and then gradually flattens out toward a value of 0 where I am not
satisfied with it at all.
Regardless of how we arrived at the satisfaction value, our range for this value
is 0 to 100. We can even think of it as a percentage of satisfaction. (Note that we
don't need a lot of granularity here. Therefore, we don't need to use a decimal
value. A
byte
type to store the values of 0 to 100 performs just fine in this regard.)
Once we have determined our satisfaction with all five blades, we can then compare
them and decide which one we are going to use.
In other examples, my daughter, Kathy, needed ways of measuring the worth of
various topics that she wanted to put into her speech for her fifth grade election
campaign. I needed a way of rating the quality of the food and the atmosphere at a
particular restaurant when I took my family out to dinner. We could have even put
a subjective value on the sense of altruism that we felt by giving more than was nec-
essary in the Ultimatum Game.
Of course, it is certainly feasible for us to track
both
the value and the utility
separately. This is often the case when the corresponding
subjective utility
for a
concrete number
of items may change based on other parameters. In our $20 bill
