Persuasive Communication - How Audiences Decide. 2nd Edition

10 Understanding Rational Decision Making

client’s business problems were independent of the audience. From the new MBA’s perspective, his

client simply needed to plan his new business “correctly.”^57

Some expert audience members put an extremely high premium on getting information that

addresses their decision criteria. A study of the responses of business executives to two business

communication students’ memos actually found an inverse relationship between the students’

level of knowledge of and skill in business communication and the executives’ ratings of the two

students’ memos. To the researcher’s surprise, the executives rated the memo composed by the

high-knowledge, highly skilled business communication student as ineffective. And despite the

less skilled student’s poor spelling, incorrect grammar, tortured syntax, lack of knowledge about

business genres, and inability to defend a point of view, the executives rated his memo as highly

effective. Why? As one of the executives explained, the strength of the less skilled student’s memo

was that it included “suffi cient information for decision making.”^58

Expert audiences also expect professionals to avoid presenting information that does not address

their decision criteria. Purchasing agents react negatively to sales presentations that include infor-

mation irrelevant to their decision criteria. Purchasing agents have especially negative reactions

to salespeople who begin their initial sales calls with in-depth descriptions of the selling fi rm’s

organization chart.^59 Similarly, apartment seekers are more persuaded by recommendations that

exclude features or benefi ts that are irrelevant to their decision criteria than by recommendations

that include such features.^60 A think-aloud study of venture capitalists reading business plans fi nds

“the thrust of the [venture capitalists’] protocol comments was that venture proposals should be

short documents that provide the major pieces of information the venture capitalist needs to make

a decision.”^61

It’s important for professionals to remember that the criteria they use to make decisions probably

differ from the criteria their audiences use. For example, physicians rarely use the same decision crite-

ria to decide among possible treatments that their patients use.^62 Professionals also need to remember

that arguments based on their own criteria will probably fail to persuade their audiences. Research

shows that health guidelines for patients are less effective than they could be because they are usually

written from a physician’s perspective and tend to downplay the criteria most important to patients.^63

Techniques for Discovering and Using Audience Decision Criteria

Two of the more commonly used techniques for teasing out experts’ decision criteria and their

weights, or degree of importance, are Multi-Attribute Utility Analysis^64 and the Analytical Hier-

archy Process.^65 Both techniques fi rst elicit a set of decision criteria from the experts and then

determine the weights experts assign them. Decisions computed by the resulting models tend

to agree with experts’ actual decisions with an average convergent validity ranging from 0.70

to 0.95.^66 Not surprisingly, the models generated by the two techniques tend to yield similar

decisions.^67

Persuasive documents based on the models generated by these techniques have been empirically

tested by real audience members. One study used multi-attribute utility models of renters’ decision

criteria to automatically generate arguments for choosing specifi c apartments. The arguments

generated successfully persuaded real renters to choose the apartment the model recommended.^68

Another study used a multi-attribute utility model of several hundred hospital patients’ decision

criteria to write a brochure that persuaded many to get fl u shots. Of those patients who received

the model-based brochure, 64% obtained fl u shots compared to only 34% of the control group

who received a brochure written, as is typically done, without the benefi t of the model. A second

model-based brochure improved patient compliance rates to Pap smear procedures by approxi-

mately 15% over rates achieved with conventionally produced brochures.^69