Persuasive Communication - How Audiences Decide. 2nd Edition

Aids to Audience Decision Making 163

Hand gestures can play an important role in listeners’ comprehension and memory especially

when the speaker’s message is somewhat ambiguous. Emblematic gestures, such as the OK sign or

extending two fi ngers to signal two, are particularly helpful in aiding memory for verbal informa-

tion. One study found that listeners recalled 34% of a message when the speaker accompanied it

with emblematic gestures, 11% when the speaker accompanied it with emphasizing gestures, and

only 5% when the speaker did not make any gestures.^197

Other congruent nonverbal behaviors, such as head nodding, eye movements, and lip and facial

movements, can also improve listeners’ comprehension of the speaker’s message.^198 However, some

types of information may be equally well understood even when listeners cannot see the speakers’

nonverbal behaviors. Apparently, college students who listen to audio recordings of lectures can

comprehend just as much of the lectures as those who attend the actual lectures.^199

Pictorial Illustrations

In addition to capturing attention and promoting recall,^200 pictorial illustrations (e.g., photos, draw-

ings, and video clips) in documents and presentations can aid sentence comprehension.^201 Pictures

on warning labels, for example, both capture attention^202 and increase readers’ comprehension of

the warnings.^203 Whether pictorial illustrations of events and activities are static pictures, such as

still photographs, or video footage, they can often enhance comprehension equally well.^204

Pictorial illustrations are more likely to aid sentence comprehension when they provide visual

referents to the words in the sentences audiences read or hear. Thus, related words and pictures

presented together enhance comprehension and recall more than the same words and pictures pre-

sented separately.^205 A study of the effects of pictorial illustrations on learning fi nds that students

given instructional materials combining text and pictures learn signifi cantly more than those given

the same materials without illustrations.^206 Moreover, a review of 46 experimental studies fi nds

that in 81% of the studies, readers’ comprehension was better for text and pictures than text alone.

Readers with poor reading skills performed 44% better on average with text and illustrations than

with text alone. More skilled readers performed 23% better.^207

Pictorial illustrations will not enhance comprehension if they are irrelevant to the accompany-

ing sentences^208 or if they are placed too far from the sentences to which they refer.^209 Neither

will pictures enhance comprehension if their implications are redundant with the implications of

the information presented verbally.^210 A study that compared seven different versions of a users’

manual for a new telephone system found that the “words only” version enabled consumers to

follow the instructions most quickly and accurately. Consumers actually had more diffi culty fol-

lowing the instructions when pictures of the steps accompanied verbal descriptions of those same

steps.^211 In a similar way, pictures of products can interfere with consumers’ attempts to integrate

verbal descriptions of the products’ attributes and, as a result, negatively impact consumers’ evalua-

tions of the products pictured.^212

The effects of pictorial illustrations on comprehension also depend on characteristics of

the pictures themselves, such as the perspective from which they are taken.^213 When text and

pictures intended to work together are poorly written, poorly visualized, contradictory, or not

complementary, the audience’s comprehension will suffer.^214 Comprehension will also suffer

when the sentence or caption to which the picture refers captures the audience’s attention

before the picture captures their attention, particularly if the sentence or caption is high in

visual imagery.^215

The effects of pictorial illustrations on comprehension also depend on characteristics of the

audience. In some cases, pictures only have a positive effect when the audience has little initial

interest in the information presented.^216 In other cases, only novices in a domain will benefi t from

the addition of pictorial illustrations—experts may fi nd pictures distracting.^217