Cognitive Processes in Audience Decision Making 125Viewers of graphs, like readers and viewers of images, may conduct either type of search. Graphviewers will conduct a general search if they are simply asked to describe a graph’s meaning. In a study
that asked viewers to describe the meaning of a line graph, viewers fi rst read the title, inspected the
graph, and then began to slowly identify the graph’s variables and referents. After conducting this type
of general search, one of the viewers in the study described the line graph as follows:
This is vocabulary score vs. age by TV watched in hours. And it shows that vocabulary
scores increase with age very dramatically for someone who watches a lot of TV and not so
dramatically for someone who watches a little TV.^197More often, the information an audience extracts from a graph depends on their reason forlooking at the graph.^198 According to one schema-driven model of graph comprehension, viewers
fi rst pose a question about the variables in a graph. For example, the question, “What was the aver-
age per capita income in France in 2014?” could be answered if the graph contained three variables:
per capita income , France , and 2014. Viewers next search the graph’s legend and axes for the variables
in their question. In the last step viewers identify the relevant value, for example, the amount of
income people in France made on average in 2014, or $42,732. In this model graph viewers do
not try to comprehend everything about the graph as they would in a general search. Instead they
target their search of the elements in the graph to get the answer to their particular question.^199
Attribute-Based vs. Alternative-Based Search
When audiences conduct a targeted search within a text or table in order to make a decision, they
use one of two basic search patterns. One search pattern is termed attribute-based search. Such a
search pattern could also be called “criterion-based” search since attributes are one type of decision
criterion. The other search pattern is alternative-based search.^200 This search pattern could also be
called “benchmark-based” search since alternatives are one type of benchmark.
Brain Regions Activated. Both attribute-based and alternative-based searches are coordinatedby the ventromedial prefrontal cortex (vmPFC) of both hemispheres (see Figure 3.5 , p. 108).^201
Unlike healthy individuals who normally conduct attribute-based searches, people with damage to
the vmPFC routinely use alternative-based search when faced with a multi-attribute decision.^202
Our model of decision making depicts search as attribute based. Attribute-based search is illus-trated in the following passage in which a renter thinks aloud as she decides which apartment to
rent, A or B. Notice how she fi rst compares both apartments with respect to the cost to rent each
of them. Then she compares both apartments with respect to the noise level of each:^203
OK, we have an A and a B.
First, look at the rent for both of them.
The rent for A is $170 and the rent for B is $140.
$170 is a little steep, but it might have a low noise level.
So we’ll check A’s noise level.
A’s noise level is low.
We’ll go to B’s noise level.
It’s high.
Gee, I can’t really very well study with a lot of noise.
So I’ll ask myself the question, “Is it worth spending that extra $30 a month,
to be able to study in my apartment?”