There is a lot of buzz around Persuasion, Emotion and Trust (PET
design) going on now. Sure, human factors / usability is still
important: if the user can’t find it, the product / function still
isn’t there. Usability is not going away.

But the field IS becoming more interesting. Methods for deriving
navigation architectures and best practices for designing effective
layout are established. Now the leading edge is exploring
evidence-driven methods to describe information exploration and
decision patterns. The question is not “Can they buy the argyle socks?”
but rather, “What experience will drive consumers toward buying OUR
argyle socks?”

So attention has shifted from ensuring that sites allow people to take
specific sub-actions (complete a purchase), to designing sites that
encourage people to take larger, business-driven actions. Actions can
be anything from buying… argyle socks (!), to joining a club, to
signing-up for a specific 401K plan, to advocating for one’s own
healthcare. The key, though, is that the site content should influence


Measuring persuasion is one of the field’s current challenges.
Marketing often uses attitude measures to evaluate how persuasive an ad
or a website is. To do this, they measure how positively or negatively
consumers feels about a product or toward a service. Then they expose
consumers to ads or sites or even the actual product. And they measure
again. The delta between the first and the second measure is used as an
index of how persuasive (or not) the ad / site / product was.

This seems logical. But organizations aren’t really interested in
attitudes. They are interested in action. And there is often an
uncomfortably loose link between the attitudes consumers report and
whether they ultimately act on those attitudes. As an example: I have a
strong positive attitude about Ducati motorcycles. Every ad I see,
every (reasonably frequent) visit to the website, and every
conversation with motorcycle enthusiasts increases that positive
feeling. But I’m not likely to buy one. Not very soon, anyway.

If attitudes are not an effective measure for persuasion, what should we measure?

A recent series of studies by Rucker, Petty & Briñol (2008)
suggest that “attitude certainty” predicts “behavioral intention” (or
likelihood to act) better than direct attitude measures. As an added
benefit, along the way their work also addresses the common marketing
question — is it better to present only the benefits of the product,
or to present both the benefits and potential drawbacks?


Rucker and team developed a series of experiments that manipulated /
controlled the presentation of various elements of selling
communications for products ranging from cell phones to bicycles to
toothpaste to portable DVD players to medicine. Overall, the messages
were positive. Critically, in half the tests consumers were presented
with only positive information (one-sided frame). In the other half
consumers were explicitly presented both pros and cons of the product
(two-sided frame condition). Across their experiments they found:

– One-sided and two-sided messages can both increase positive attitudes toward a product.
– Two-sided messages are more effective at instilling consumers with confidence in that attitude.
– Individuals who know a lot about something are less influenced
by message framing (two- vs. one-sided) They are already confident
about their attitude.
– People remembered about the same number of positive and
negative product details in both the one-sided and two-sided messaging
— frame does not influence recall of product details.
– People who were exposed to both pros and cons (two-sided)
indicated a greater intention to buy than those exposed only to pros —
even though both had developed positive attitudes toward the product.


Yesterday, I looked at apartments with a friend in Los Gatos. Each
place had selling points. Each also had drawbacks. To sort which
apartment was most desirable, we made a list. Doing that made the
decision process feel more solid. Ordered. Complete. Informed. Before
the list, we were doing cost / benefit analysis in our respective
heads. After the list, we felt more confident about a decision. All of
the critical elements of the various places were surfaced and

Rucker, Petty & Briñol (2008) suggests that presenting a
two-sided frame instills the same sort of confidence. People who are
exposed to a one-sided frame know consciously that they still need to
think about the drawbacks of a given decision. And — worse for
persuasion design — they are left to generate the negatives on their
own. In contrast, people who are exposed to a two-sided frame are left
with the impression that the communication is complete. At a
meta-cognitive level, the reader seems to assume that the communicator
has comprehensively considered and presented both positives and
negatives. As a result, the consumer doesn’t need to expend energy
generating and considering the cons before they can make a good
decision. Somebody has already done that for them.


In thinking about this study, it is critical to differentiate between
content that creates a positive attitude and content that also leaves
consumers confident that their conclusions are correct. The persuasion
literature highlights why:

– Confidently held attitudes influence behavior more than attitudes held with less certainty. Rucker & Petty (2004)
– Confidently held attitudes are more likely to persist over time. (Petrocelli, Tormala & Rucker, 2007)
– Strongly held attitudes are more resistant to change tactics
than attitudes held with less certainty. Rucker & Petty (2004)

As Rucker and colleagues point out, politicians seeking to create
loyalists or companies wanting to create advocates should create
content that persuades. But critically, they also should strive to
create content that instills confidence. Presenting both pros and cons
seems to be one way to do that.

References for this newsletter are posted at: