Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> This article reports 4 experiments concerning the effect of repetition on rated truth (the illusory truth effect). Statements were paired with differentially credible sources (true vs. false). Old trues would be rated true on 2 bases, source recollection and statement familiarity. Old falses, however, would be rated false if sources were recollected, leaving the unintentional influence of familiarity as their only basis for being rated true. Even so, falses were rated truer than new statements unless sources were especially memorable. Estimates showed the contributions of the 2 influences to be independent; the intentional influence of recollection was reduced if control was impaired, but the unintentional influence of familiarity remained constant <s> BIB001 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> According to a two-step account of the mere-exposure effect, repeated exposure leads to the subjective feeling of perceptual fluency, which in turn influences liking. If so, perceptual fluency manipulated by means other than repetition should influence liking. In three experiments, effects of perceptual fluency on affective judgments were examined. In Experiment 1, higher perceptual fluency was achieved by presenting a matching rather than nonmatching prime before showing a target picture. Participants judged targets as prettier if preceded by a matching rather than nonmatching prime. In Experi- ment 2, perceptual fluency was manipulated by figure-ground contrast. Stimuli were judged as more pretty, and less ugly, the higher the con- trast. In Experiment 3, perceptual fluency was manipulated by presen- tation duration. Stimuli shown for a longer duration were liked more, and disliked less. We conclude (a) that perceptual fluency increases liking and (b) that the experience of fluency is affectively positive, and hence attributed to positive but not to negative features, as reflected in a differential impact on positive and negative judgments. 0 <s> BIB002 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> We explored the role that poetic form can play in people's perceptions of the accuracy of aphorisms as descriptions of human behavior. Participants judged the ostensible accuracy of unfamiliar aphorisms presented in their textually surviving form or a semantically equivalent modified form. Extant rhyming aphorisms in their original form (e.g., “What sobriety conceals, alcohol reveals”) were judged to be more accurate than modified versions that did not preserve rhyme (“What sobriety conceals, alcohol unmasks”). However, the perceived truth advantage of rhyming aphorisms over their modified forms was attenuated when people were cautioned to distinguish aphorisms' poetic qualities from their semantic content. Our results suggest that rhyme, like repetition, affords statements an enhancement in processing fluency that can be misattributed to heightened conviction about their truthfulness. <s> BIB003 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> This experiment demonstrated that rating the credibility of nonfamous faces results in a significant increase in rated credibility on a subsequent encounter relative to new nonfamous faces. The degree of credibility enhancement is comparable for both honesty and sincerity ratings and at both short (2-day) and long (14-day) interrating intervals. Furthermore, credibility enhancement was independent of recognition; ratings were significantly higher for repeated faces, regardless of whether they were remembered. Although female faces were rated more credible than male faces, there was no gender difference in the degree of credibility enhancement with repetition. Conditional analyses revealed that actual, rather than perceived, repetition formed the basis of credibility enhancement. Future research should compare repetition effects on both credibility and affect as well as the durability of such effects over time. <s> BIB004 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> We propose that aesthetic pleasure is a function of the perceiver’s processing dynamics: The more fluently perceivers can process an object, the more positive their aesthetic response. We review variables known to influence aesthetic judgments, such as figural goodness, figure–ground contrast, stimulus repetition, symmetry, and prototypicality, and trace their effects to changes in processing fluency. Other variables that influence processing fluency, like visual or semantic priming, similarly increase judgments of aesthetic pleasure. Our proposal provides an integrative framework for the study of aesthetic pleasure and sheds light on the interplay between early preferences versus cultural influences on taste, preferences for both prototypical and abstracted forms, and the relation between beauty and truth. In contrast to theories that trace aesthetic pleasure to objective stimulus features per se, we propose that beauty is grounded in the processing experiences of the perceiver, which are in part a function of stimulus properties. <s> BIB005 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> Human reasoning is accompanied by meta-cognitive experiences, most notably the ease or difficulty of recall and thought generation and the fluency with which new information can be processed. These experiences are informative in their own right. They can serve as a basis of judgment in addition to, or at the expense of, declarative information and can qualify the conclusions drawn from recalled content. What exactly people conclude from a given meta-cognitive experience depends on the naive theory of mental processes they bring to bear, rendering the outcomes highly variable. The obtained judgments cannot be predicted on the basis of accessible declarative information alone; we cannot understand human judgment without taking the interplay of declarative and experiential information into account. <s> BIB006 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> Although people routinely estimate the value of items in their environment, from goods and services to natural resources and lost earnings following an accident, the processes that underlie human valuation estimates are not well understood. We show that people use familiarity and fluency—the ease with which they process information—to determine an item’s value. In three experiments, participants believed that familiar forms of currency (e.g., a familiar $1 bill) had greater purchasing power than their unfamiliar counterparts (e.g., a rare and unfamiliar coin). Mechanistic analyses showed a positive correlation between participants’ familiarity with the unfamiliar currency and their estimates of its value. We conclude by discussing the theoretical and practical implications of our findings for researchers, marketing experts, and policymakers alike. <s> BIB007 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> Experiencing difficulties during information processing can either be used as signal for the increased need of cognitive effort (“try harder”), or as avoidance signal for future action selection (“avoid and switch”). These alternative ideas are currently reflected in two seemingly opposing theories of anterior cingulate cortex function, namely the conflict monitoring versus the outcome evaluation account. Botvinick (2007) recently suggested that both positions might converge on the detection of aversive signals. Here, we will show that low perceptual fluency, which is known to evoke negative affective reactions, triggers the mobilization of cognitive effort even in the absence of response conflicts. More precisely, in three experiments effort adjustments in reaction to fluency manipulations as indicated by significant interactions of Fluency N × FluencyN−1 were found. It follows that an aversive signal (here: low fluency) is not only used for effort prediction but also for effort adjustments. <s> BIB008 </s> Designing persuasive health materials using processing fluency: a literature review <s> Nature of PF and its effects <s> Processing or cognitive fluency is the experienced ease of ongoing mental processes. This experience infl uences a wide range of judgments and decisions. We present a general model for these fluency effects. Based on Brunswik’s lens-model, we conceptualize fluency as a meta-cognitive cue. For the cue to impact judgments, we propose three process steps: people must experience fluency; the experience must be attributed to a judgment-relevant source; and it must be interpreted within the judgment context. This interpretation is either based on available theories about the experience’s meaning or on the learned validity of the cue in the given context. With these steps the model explains most fl uency effects and allows for new and testable predictions. <s> BIB009
Every cognitive task, such as reading health materials, can be described along a continuum from effortless to highly effortful. This cognitive effort produces a corresponding metacognitive experience, which ranges from fluent to disfluent. Human judgment is influenced not only by the information content but also by the metacognitive experience of processing that information   . For example, health materials that are written with familiar, simple words are easy to read and understand, and therefore assumed to be fluently processed, i.e., they possess lexical fluency. In contrast, materials that include a number of unfamiliar jargon terms are hard to read and understand, and therefore assumed to be disfluently processed. There are various types of fluency, as discussed below (e.g., syntactic, phonological, and retrieval fluency; for a review, see  ); however, their effect on judgment is uniform: fluently processed stimuli generate a positive judgment among recipients  . More precisely, compared with less fluent stimuli, fluently processed stimuli are generally rated as follows: more pleasing BIB002 ; more trustworthy BIB001 BIB003 ; more valuable BIB007 ; more honest and sincere BIB004 ; and safer  . Fluently processed stimuli also have numerous other favorable attributes (for reviews, see  BIB005 ). The manner in which the PF effect works has been explained by the hedonic marking hypothesis BIB002  , attributional accounts BIB009 , and naive theories BIB006 . Recent studies have focused largely on naive theories to account for context-specific interpretations of the PF effect (for reviews, see BIB005 BIB006 ). Processing fluency also influences a recipient's willingness to undertake a given task. The experience of fluent processing has been repeatedly demonstrated to serve as an affective signal. In general, high PF generates a positive affect, whereas low PF produces a negative affect  . The positive affect is a source of positive attitude, which is an antecedent to behavioral intention  . Processing fluency is used to predict the effort necessary for a given task; accordingly, it has an impact on willingness to do a task (discussed below) BIB008 . More precisely, low PF serves as an aversive signal and reduces willingness to engage in the given task BIB008 . For example, health materials that are presented in a small, hardto-read font and use jargon terms and complex syntax cannot be processed fluently. Consequently, readers will suppose that greater effort is needed for the given task and are more likely to resist the health message-partly because of disfluency. The reverse also applies.