The Relation Between Syntactic Complexity and Advertising Persuasiveness

ABSTRACT - Verbal aspects of advertising have long been of obvious interest and importance in marketing research. However, a psycholinguistic approach has rarely been used to study verbal representations. Two important aspects of psycholinguistic theory are useful in the study of advertising effects: semantics and syntax. At the simplest level, semantics involves the study of meaning while syntax involves the study of sentence structure.

Citation:

Tina M. Lowrey (1992) ,"The Relation Between Syntactic Complexity and Advertising Persuasiveness", in NA - Advances in Consumer Research Volume 19, eds. John F. Sherry, Jr. and Brian Sternthal, Provo, UT : Association for Consumer Research, Pages: 270-274.

Advances in Consumer Research Volume 19, 1992      Pages 270-274

THE RELATION BETWEEN SYNTACTIC COMPLEXITY AND ADVERTISING PERSUASIVENESS

Tina M. Lowrey, University of Illinois, Urbana-Champaign

ABSTRACT -

Verbal aspects of advertising have long been of obvious interest and importance in marketing research. However, a psycholinguistic approach has rarely been used to study verbal representations. Two important aspects of psycholinguistic theory are useful in the study of advertising effects: semantics and syntax. At the simplest level, semantics involves the study of meaning while syntax involves the study of sentence structure.

Most of the past advertising research using psycholinguistic theory has focused on semantic components of advertising messages, such as word meanings and inference-making. There has been very little empirical work on the effect of syntactic structure on the persuasiveness of advertising.

A pilot study was conducted to investigate these issues. Using the Elaboration Likelihood Model as a framework, advertisements were created that differed in level of syntactic complexity and argument strength. It was hypothesized that attitudes toward the product advertised would differ most greatly for simple versions depending on argument strength, due to elaborative thinking (i.e., bolstering for strong versions and counter-arguing for weak versions). It was also hypothesized that attitudes toward the product advertised would not differ as greatly for complex versions across levels of argument strength. Results upheld these predictions.

INTRODUCTION

Verbal aspects of advertising, although important in marketing research, have rarely been studied utilizing a psycholinguistic approach. Most of the past advertising research using psycholinguistic theory has focused on semantic components of advertising messages, such as word meanings and inference-making. For example, concrete words have been found to be better than abstract words in producing visual imagery (Rossiter & Percy, 1980). In addition, copy that invites readers to make inferences has been found to be particularly misleading (Harris, 1977; Harris, Dubitsky & Bruno, 1983).

Psycholinguistic research which focuses on syntax has shown that complex sentence structures are less easily comprehended than simple sentence structures. In addition, complex sentences are less likely to be recalled than simple sentences. Specific structures that have been shown to reduce the comprehensibility of text include passive construction, negation, and left-branching sentences.

For example, fewer errors are made when recalling affirmative and active sentences than when recalling negative and passive sentences (Mehler, 1963; Miller, 1962). Similarly, when subjects are asked to verify the truth or falsity of a sentence that describes a pictorial stimulus, response latencies are faster for affirmative and active sentences than for negative and passive sentences (Clark & Chase, 1972; Gough, 1965, 1966; Just & Carpenter, 1971; Slobin, 1966; Trabasso, Rollins, & Shaughnessy, 1971; Wason, 1959, 1965).

Left-branching structures can cause processing difficulties by overloading working memory, particularly in children and older adults. Even for adults with normal capacity, however, such structures can impede comprehension when combined with other factors that place demands on short-term memory (for a thorough discussion of these issues, see Anderson & Davison, 1988).

Syntactic aspects of advertising have been addressed in studies of the miscomprehension of corrective advertising (Jacoby, Nelson & Hoyer, 1982) and in suggested copywriting guidelines (Percy, 1982; Rogers, 1988). Research in corrective advertising has replicated previous findings (Gough, 1965, 1966; Miller, 1962; Slobin, 1966) that affirmations are better comprehended than negations.

The copywriting guidelines which have been outlined look to general psycholinguistic theories of syntax effects for their framework, but to date little empirical evidence exists to support such guidelines in the context of advertising. These guidelines advise copywriters to write short headlines, and to avoid negations (e.g., "7-Up does not contain caffeine") and passive constructions (e.g., "Advil is recommended by more doctors"). However, the relation between syntactic complexity and persuasion has not been investigated. Indeed, the nature of the relation between syntactic complexity and comprehension is unclear. It would be particularly useful for researchers to show empirically that syntax has direct implications for predicting the persuasiveness of message content. A psycholinguistic approach could contribute a great deal to our understanding of how verbal aspects of advertising influence persuasion.

There are several ways in which complexity can be manipulated in the context of advertising. Affirmative statements vs. negations are one way of varying the level of complexity. For example, "Trident gum is sugarless" is syntactically less complex than "Trident gum does not contain sugar." Active vs. passive structures are another way of manipulating complexity. According to existing theory, "More people prefer the taste of Pepsi" is easier to process than "The taste of Pepsi is preferred by more people." Left-branching sentence structures can also contribute to complexity. For example, "Because you care about your health, you should try Healthy Choice entrees" requires more memory capacity than "You should try Healthy Choice entrees because you care about your health."

Psycholinguistic research has shed light on comprehension processes utilizing methods that do not attempt to measure persuasion. Persuasion is not an essential outcome in most reading situations, which are the situations of primary interest to psycholinguists. However, persuasion is a very important outcome in the study of advertising. In this study, attitudes were measured, in addition to memory and comprehension, in an effort to investigate the interaction between syntax, comprehension, and persuasion in advertising.

There are two persuasion models that have implications for predicting the effect of syntactic complexity on persuasion. The first of these is the traditional information-processing approach to persuasion. Information-processing theory (IPT) considered message comprehension and retention to be important antecedents of persuasion (Hovland, Janis & Kelley, 1953; McGuire, 1966; 1969). It was hypothesized that enduring attitude change could not occur without comprehension and retention of the persuasive message. In fact, IPT would predict that as the complexity of a message increases, comprehensibility is reduced, leading to reduced persuasiveness as well. The second model that has implications for predicting the effect of syntactic complexity on persuasion is the Elaboration Likelihood Model (ELM - Petty & Cacioppo, 1986). The ELM takes into account several variables that affect both the ability and motivation to process incoming information.

Ability factors include, but are not limited to, distraction, message repetition, and message complexity-comprehensibility. For example, if one is distracted from attending to the message, it becomes difficult to process the information. This is also true if one cannot comprehend the message.

The ELM also considers motivation to process to be a key factor in the persuasion process. Factors that affect level of motivation include, but are not limited to, personal relevance, responsibility and message sources. For example, the more personally relevant a particular advertisement is (e.g., relevant to future decisions one anticipates making), the more one may be motivated to pay attention to it and elaborate on it. Both ability to process and motivation to process are important determinants of the amount of elaboration that is likely to occur when exposed to a message.

The ELM would predict that as the complexity of a message increases, comprehensibility is reduced. However, the predictions of each theory about the effects of complexity on persuasion would differ as a function of message strength. As stated previously, IPT would predict that as a message becomes less comprehensible it should become less persuasive, regardless of the message content. The ELM's predictions would be identical to those of IPT only for strong messages (e.g., messages with compelling arguments). That is, if ability to process a strong message is impaired, persuasiveness should be reduced due to the reduction in support arguments that would normally be elicited. However, if the message is weak (e.g., contains arguments which are not compelling), the ELM would predict the opposite effect. As ability to process a weak message is impaired, persuasiveness should be enhanced due to the reduction in counterarguments that would normally be elicited.

Although the ELM and IPT differ with respect to their predictions of the effects of message complexity on persuasiveness, both models agree that extreme levels of complexity should overload working memory which, in turn, should impair the ability to process the message, even if motivation to process is high. In the context of advertising, however, it is important to address the role that lesser degrees of complexity may have in the persuasion process. Advertising is designed to be comprehensible to the majority of adults with average language skills. Advertisements may be differentiated, then, in terms of the amount of effort required to reach comprehension, not in terms of absolute comprehensibility.

Because complexity requires greater processing effort, motivation to process the message should be a key determinant of the effect of complexity on persuasion. Under situations of moderate personal relevance (moderate involvement), complex syntax may serve to decrease one's motivation to process a message even if the ability to process exists. If one is not highly involved when a complex message is encountered, one might not bother to read the message. If so, syntactic complexity may have a direct effect on the persuasiveness of the message. According to ELM, if message arguments are strong, complexity should serve to decrease message persuasiveness. If message arguments are weak, complexity should serve to increase message persuasiveness.

The pilot study reported herein was designed specifically to address this issue with special attention paid to the levels of complexity and exposure conditions frequently encountered in advertising contexts, as a simple demonstration of the main effect of syntactic complexity on advertising persuasiveness, holding motivation to process constant.

METHOD

IPT and ELM offer two conflicting sets of predictions regarding the relation between message comprehension and persuasiveness. The main purpose of this study was to demonstrate the relevance of the ELM in predicting the effect of syntactic complexity on the persuasiveness of advertising messages. This study focused on the effects of low and moderate levels of complexity on advertising persuasiveness under situations of moderate personal relevance (moderate involvement). Four advertisements for a product (a breakfast cereal) were created that differed in their syntactic complexity and their argument quality (a 2 X 2 factorial design), as follows:

1) Simple syntax - strong advertising claims

2) Simple syntax - weak advertising claims

3) Complex syntax - strong advertising claims

4) Complex syntax - weak advertising claims

HYPOTHESES

IPT would predict that, regardless of message strength, simple messages would be more persuasive than complex messages. The ELM would predict that, in a moderate involvement situation, subjects should be more likely to engage in elaborative processing when processing simple vs. complex versions. Thus, syntactic complexity may serve to increase persuasion by reducing the number of counterarguments normally elicited by a weak message and to decrease persuasion by reducing the number of support arguments normally elicited by a strong message. This study was designed to assist in determining which model is likely to predict effects at moderate levels of complexity.

For all subjects, it was hypothesized that simple versions would produce greater levels of recall and recognition of advertising content than would complex versions, as consistent with predictions of both IPT and ELM. More importantly, it was hypothesized that the effect of syntactic complexity on persuasion would depend on message strength. For simple (easy to process) ads, product evaluations should be less favorable for weak argument versions than for strong argument versions. For complex (hard to process) ads, product evaluations should not differ as greatly across levels of argument strength.

SAMPLE

57 students from the introductory advertising class at the University of Illinois participated in this study. The data from one foreign subject and three subjects who failed to follow instructions were eliminated.

PROCEDURE

All subjects received a booklet containing several advertisements. The target ad was embedded within this booklet. In an effort to hold involvement constant at a moderate level, the product chosen for the target ad (a breakfast cereal) is one that is not generally considered a high involvement product.

The strong and weak versions of the ad were created by pre-testing strong and weak arguments for the product chosen. Examples of strong arguments include that it tastes good, is low-fat, and has crispy flakes. Examples of weak arguments include that it has light-weight packaging, comes in a small box that is easy to store, and is available at many stores.

The syntactically simple versions of the claims were written in the affirmative, active voice with right-branching structure. Complex versions were created by transforming the simple versions into negations and left-branching, passive structures. In addition, pre-tests using the Cloze procedure (Taylor, 1953) were conducted to ensure that the versions were differentiated in terms of comprehensibility. The Cloze procedure involves replacing every nth (e.g., fifth, tenth, etc.) word from a passage of text with a blank. Pre-test subjects are asked to fill in the blanks. Readability scores are then computed by summing the number of correctly replaced words within the passage of text.

After reading through the advertisement booklet, subjects received the measurement booklet. Attitude toward the target product was assessed first, followed by a measurement of purchase intention. These measures were followed by a free recall task of the target ad content, wherein subjects were asked to list any information about the target product they could remember. Subjects were than presented with a standard thought-listing measure in order to assess cognitive responses toward the target product (Cacioppo & Petty, 1981). This was followed by an aided recognition task where subjects were asked specific questions about the target product (based on statements that appeared in the ad). Finally, subjects responded to manipulation check items, including rating the comprehensibility of the target ad (Wang, 1970).

RESULTS

Only the results from the recall task and attitude measure are reported here. The average numbers of claims recalled by subjects are shown in Table 1. Although the pattern reflects the predictions, the main effect of syntactic complexity was only marginally significant (F(1, 51)=3.344; p<.08).

Subjects responded to a 9-point scale to assess their attitude toward the breakfast cereal (1=very negative; 9=very positive). Mean attitude scores along this 9-point scale are shown in Table 2. The pattern of means reflected the predictions, and the argument strength X syntactic complexity interaction was statistically significant (F(1, 51)=4.633; p<.04). Specifically, subjects who read the easy, yet weak version of the advertisement had more negative attitudes than did the subjects who read the easy and strong version. The attitudes of subjects who read the hard version of the advertisement did not differ as greatly across levels of argument strength.

DISCUSSION

This pilot study demonstrated that syntactic complexity can serve either to increase or decrease persuasion, independently of its effects on comprehension. Thus, this study showed that syntactic complexity can have direct implications for the persuasiveness of advertising messages.

Specifically, it was hypothesized that easy versions of ads would produce greater levels of recall than hard versions, regardless of argument strength. This pattern held true.

More importantly, it was hypothesized that, for easy ads, product attitudes would be less favorable for weak argument versions than for strong argument versions. For hard ads, product attitudes were not expected to differ as greatly across levels of argument strength. The argument strength X syntactic complexity interaction was statistically significant, thus upholding these predictions as well.

In addition to the results reported here, analyses of other measures included in this study have yet to be conducted, including purchase intention, aided recognition, and cognitive responses. It is hoped that these additional analyses will yield similar results.

Future research should also address alternative explanations of these results. One interpretation of such results is that the motivation to process the ad is reduced when extra effort is required. However, this study did not determine whether syntactic complexity is reducing motivation to process the message or impairing ability to process the message. The same results might be obtained if subjects weren't able to process the complex version. It could be true that the complex syntax overloads processing space. A study designed to investigate this issue is planned.

TABLE 1

AVERAGE NUMBER OF CLAIMS RECALLED BY LEVEL OF SYNTACTIC COMPLEXITY

TABLE 2

MEAN ATTITUDE SCORES BY ARGUMENT STRENGTH AND SYNTACTIC COMPLEXITY

This study, in conjunction with proposed future studies, lays a groundwork for exploring the diverse ways in which syntactic complexity may increase or decrease the persuasiveness of advertising. Research in these areas should contribute to our understanding of how message complexity impacts the persuasion process in the context of advertising.

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