Page 45 - The Handbook of Persuasion and Social Marketing

38 The Handbook of Persuasion and Social Marketing

elaboration has been to use an argument quality manipulation (Petty, Wells
& Brock, 1976). An argument quality manipulation typically consists of
including in one’s experiment a pair of between-subject conditions. In the
first condition, arguments are presented that are strong and compelling,
leading to the generation of favorable thoughts if people think about the
arguments. In the second condition, arguments are developed that are
weak and specious, leading to the generation of unfavorable thoughts
(counter-arguments) when people think about the arguments. The core
idea is that if a variable is getting people to attend carefully to the informa-
tion (i.e., high elaboration), then the inclusion of this variable should be
associated with increased persuasion when the arguments are strong but
decreased persuasion when the arguments are weak. To test if and how a
variable (e.g., positive versus negative mood) affects elaboration, the vari-
able is crossed with an argument quality manipulation. The effect of the
variable on elaboration is determined by the relative difference between
weak and strong argument conditions (see Rucker, et al., 2011, for a de-
tailed discussion of the argument quality tool).
As one example of how a source variable affected the amount of process-
ing using argument quality manipulation, Priester and Petty (2003) exam-
ined how the trustworthiness of a source influenced message elaboration.
Priester and Petty proposed that a message that was presented by an un-
trustworthy or biased source might receive greater scrutiny compared to
when the message came from a trustworthy source. They theorized that
because a biased source might have ulterior motives, individuals would
have to exert extra effort to examine the validity of the arguments pre-
sented compared to when the source could be trusted. Consistent with
this hypothesis, Priester and Petty found that people were more likely to
use the quality of the arguments to determine their attitudes when the
message came from an untrustworthy source. That is, the quality of the
arguments had a larger impact on attitudes when the source was untrust-
worthy than when the source was trustworthy.
Message factors can also affect the extent of message elaboration. As one
example, Smith and Shaffer (2000) examined how the presentation of a
message in a vivid and concrete fashion increased or decreased elabora-
tion. Smith and Shaffer proposed that vivid messages would increase in-
formation processing when the vivid elements were consistent with the
theme of the message itself but would lead to less processing when the
vivid elements were inconsistent with the theme of the message. Supportive
of this proposition, Smith and Shaffer (2000; experiment 2) found that
participants showed a greater discernment between weak and strong argu-
ments when the vivid aspects of a message were congruent with the theme