Comparative Advertising: a Review With Implications For Further Research

Stephen B. Ash, University of Western Ontario
Chow-Hou Wee, University of Western Ontario
ABSTRACT - The rapid growth in comparative advertising during the past decade has sparked considerable debate over the relative merits of this particular message strategy. Recent efforts to measure various effects of comparative advertising have produced interesting but often inconclusive results. A framework is proposed which provides a vehicle for evaluating research progress to date and for identifying important opportunities for future work on the topic.
[ to cite ]:
Stephen B. Ash and Chow-Hou Wee (1983) ,"Comparative Advertising: a Review With Implications For Further Research", in NA - Advances in Consumer Research Volume 10, eds. Richard P. Bagozzi and Alice M. Tybout, Ann Abor, MI : Association for Consumer Research, Pages: 370-376.

Advances in Consumer Research Volume 10, 1983      Pages 370-376

COMPARATIVE ADVERTISING: A REVIEW WITH IMPLICATIONS FOR FURTHER RESEARCH

Stephen B. Ash, University of Western Ontario

Chow-Hou Wee, University of Western Ontario

ABSTRACT -

The rapid growth in comparative advertising during the past decade has sparked considerable debate over the relative merits of this particular message strategy. Recent efforts to measure various effects of comparative advertising have produced interesting but often inconclusive results. A framework is proposed which provides a vehicle for evaluating research progress to date and for identifying important opportunities for future work on the topic.

INTRODUCTION

Comparative advertising, in one form or another, has appeared in conventional media for many years. However, there was little, if any, research interest in the topic until public endorsements were registered by the Federal Trade Commission (FTC) in a series of 1971-1972 letters and speeches. The position of the FTC was that comparative advertising would benefit consumers, and it called upon advertisers to name explicit competing brands rather than pursuing the traditional "Brand X" type of advertising. Given the apparent approval of the FTC, fears of regulatory intervention declined and the major television networks in the U.S. began to broadcast comparative advertisements with greater frequency.

To date, practitioner reactions to comparative advertising have been mixed. The FTC and its supporters from various consumer groups, professional associations and other special-interest groups still appear to endorse comparative advertising for several reasons. First, it is alleged that such advertisements provide consumers with information that was not previously available. Comparative advertising furnishes more and better information thereby assisting consumers in their choice and evaluation of products and services. Second, it is held that comparative advertising forces manufacturers to strive for product improvement. Otherwise, they run the risk of public embarrassment when their brands are positioned against superior brands in the marketplace. Finally, it is argued that such advertisements are likely to be more effective for advertisers. They have novelty, the potential for enhanced selective attention due to the mention of competing brands, and the likelihood of increased support-arguing by users of the sponsoring brand.

On the other hand, critics of comparative advertising have voiced several objections to the practice. First, they charge that comparative advertisements are prone to overloading consumers with information. A more serious consequence is that these advertisements may influence consumer choice through misidentification of brands named in the advertisement. Second, critics contend that users of competitive brands may counterargue for their brands, thereby producing a "boomerang" effect. Finally, it is argued that consumers may be duped by unscrupulous advertisers who fail to present fair and truthful comparisons or claims. Thus, the credibility of advertisements and indeed, the advertising industry in general, might be tarnished as the result of comparative advertising.

The controversy surrounding comparative advertising produced little but heated conjecture until the mid-seventies, when the key strategic issues were put in focus in a pioneer article by Wilkie and Farris (1975). In this paper, the authors not only identified the various arguments and problems in comparative advertising, but also advanced a broad set of hypotheses which were designed to generate a focused stream of research on the topic. The conceptual framework presented in Figure 1 was developed as a vehicle to organize the discussion of research findings on comparative advertising which have been reported in the literature over the past several years. The issues covered in the model are discussed below.

FIGURE 1

CONCEPTUAL FRAMEWORK OF COMPARATIVE ADVERTISING

THE CONCEPT OF COMPARATIVE ADVERTISING

The concept of comparative advertising can be pursued along two dimensions - Definitions and Types:

Definitions

Wilkie and Farris (1975) define comparative advertising as advertising that:

- compares two or more specifically named or recognizably presented brands of the same generic product or service class, and

- makes such a comparison in terms of one or more specific Product or service attributes.

Their definition is restrictive in the sense that the advertisement must not only name a competitive Brand B, but must also compare certain product attributes of the advertised brand against those of competitive Brand B.

On the other hand, McDougall (1977) takes a broader perspective by incorporating advertising forms which imply a competitive superiority on any dimension. Thus, as long as an implicit or explicit comparison is made, the advertisement would qualify under McDougall's definition as a comparison advertisement.

Based on the research conducted over the past several years, Wilkie and Farris's restrictive definition has been accepted by several researchers as a standard for comparative advertising (Belch, 1981; Golden, 1979); Goodwin and Etgar, 1980; Prasad, 1976; Swinyard, 1981). However, this definition only focuses on product-based attributes. Recent studies have included price as a dimension in comparative advertising (Della Bitta et al., 1981; Sewall and Goldstein, 1979). And, it is clear that other factors may also be used as bases for comparison. It therefore, seems appropriate to define comparative advertising as any advertisement that compares the sponsored brand against any other explicitly named competitive brand(s) along any attribute relating to product, service, price, market standing, or even company factors such as image and status.

TYPES OF COMPARATIVE ADVERTISEMENTS

McDougall (1977) identifies three types of comparative advertisements which can be classified as follows:

Comparison: An advertisement may be compared to other brands either:

a. Directly - when competing brands are named.

b. Indirectly - when competing brands are not named.

c. Generically - when competing products perform similar end uses but may differ physically.

Claim: The advertiser may compare his brand against those of competitors along some dimensions such as product attributes that are positioned as superior to those of the competitors. When a comparison is not substantiated by facts or test results, it is called a claim.

Substantiation: A claim that is supported by surveys, tests or other laboratory studies is considered as substantiation. However, a substantiated advertisement does not guarantee that the "evidence" is gathered on a fair and truthful basis, that is, neutrality of results may be questionable.

The focus of research undertaken in two recent studies (Belch, 1981; Swinyard, 1981) identifies copy claim variation as another type of comparative advertising. Within the framework of attribution theory, Swinyard explored the effects of presenting two-sided claims versus a one-sided claim in comparative advertising. Accordingly, it is possible to view a comparison advertisement as one that max include substantiated or unsubstantiated claims, and as one that may present a one-sided or two-sided view.

EFFECTIVENESS AND MEASUREMENT

Due to space constraints, it would be difficult, if not impossible, to focus on methodological issues as well as results. We have opted for the latter approach since an earlier article by Lincoln and Samli (1979) provides an extensive review of research methodologies. It is, however, interesting to note that while recent research has continued to focus on convenient, low-involvement products such as anti-perspirants (Golden, 1979), beer and cold/headache remedies (Goodwin and Etgar, 1980), grocery items (Swinyard, 1981) and toothpaste (Belch, 1981), the methodologies employed have differed considerably. Sample size has ranged from 5 (in each cell) in the Della Bitta el al. study (1981) to 594 subjects in Golden's (1979) study to a thousand single family residences in Swinyard's (1981) study. Sampling techniques have included convenience sampling using available students (Goodwin and Etgar, 1980; Golden, 1979) and two-stage clustering method (Swinyard, 1981). Most studies have reported results from laboratory experiments based on factorial between-subjects experimental designs. An important exception was the Swinyard (1981) study which employed a controlled field experiment in a full factorial design.

Recent studies Save been relatively more sophisticated in terms of the types of statistical analysis performed on data. Even though analysis of variance remains the basic analytical technique, Golden (1979) was the first researcher on this topic to use a large sample which increased the statistical power of her results. In addition, this was the first study where the data were submitted to analysis of covariance to control for the influence of brand loyalty in the dependent variable. Following Golden (1979), subsequent studies have begun to include predispositional measures and covariates during data analysis in order to remove some extraneous variance from the within-cell error term. Manipulation checks were evident in the studies by Goodwin and Etgar (1980), Swinyard (1981) and Belch (1981). Finally, note that Belch's (1981) study was the first to examine the effects of multiple exposures of comparative advertising. All previous research had investigated the effects of a single exposure.

Most of the research attention to date has centered on the effectiveness of comparative advertising as a communications tool. Virtually all of the studies which have attempted to measure the effectiveness of comparative advertising can be classified into one of two categories - hierarchy of effects model or the situational effects model (Lincoln and Samli. 1979):

The Hierarchy of Effects Model

Figure 2 shows various components of this model that have been researched in the literature

Cognitive Component The cognitive component involves two aspects awareness; and perceptions and evaluation. At issue is whether or not the comparative advertisement is actually being perceived by consumers, and if so, what are their perceptual evaluations of it.

(a) Awareness Studies conducted by Levine (1976), Ogilvy & Mather (1976, 1977) and Pride (1977) reported that there are no favorable effects for comparative advertising on consumer awareness levels. Jain and Hackleman (1978) found that the advantage of brand recall in comparative advertising over noncomparative advertising was only marginal and did not last for more than a day. Prasad (1976), however, reported that comparative advertising has a higher claim recall than noncomparative advertising. Finally, Shimp & Dyer (1978) found that noncomparative advertisements are more effective than comparative advertisements in generating consumer ability to recall copy points. In summary, the findings reported in the literature which cover the effects of comparative advertising on subject awareness are mixed. There is only marginal evidence that comparative advertising will generate greater awareness among those who are exposed.

FIGURE 2

THE HIERARCHY OF EFFECTS MODEL

(b) Perceptual Evaluations One of the alleged benefits of comparative advertising is that it can generate favorable perceptions and evaluations toward the sponsoring brand. Favorable perceptions may be governed by the extent to which the sponsored brand can be made "different" from competing brands along dimensions such as differentiation/association, believability, credibility, informativeness and comprehension. The results of several studies are summarized below:

(i) Consumers apparently do not perceive comparative advertisements to be more effective in differentiating the sponsoring brand from other brands (Ogilvy & Mather - 1976/77). The same findings apply to association where it was reported that there is no advantage in attempting to associate a sponsor's brand with a more highly regarded brand (Pride et al., 1977).

(ii) Comparative advertising may or may not generate higher believability among subjects. Some studies indicate that comparative advertising generates high believability (Wilson, 1976) while others suggest that it results in lower believability (Ogilvy and Mather, 1976/77; Shimp and Dyer, 1978). Still others have shown that there is no significant difference in impact on believability between comparative and noncomparative advertising (Golden, 1979).

(iii) Related to believability is the notion of credibility of claims. Golden's (1979) study indicates that there is no significant difference in the credibility of claims between comparative and noncomparative advertising, while in Prasad's study (1976), consumers perceive a lower credibility of claims made in comparative advertisements. Wilson and Muderrisoglu (1979) and Swinyard (1981) also support the lower credibility of claims made through comparative advertising.

In summary, believability and credibility differences may be due to several factors, including counter arguments and source derogations (Mazis, 1976, Wilson et al., 1980, Swinyard, 1981). In fact, some studies (Wilson et al., 1980; Swinyard, 1981; Belch, 1981) have reported that recipients of comparative advertising experienced significantly more negative thoughts and counter-arguments than did recipients of noncomparative advertising. Other factors that may affect believability and credibility include various situational factors and these will be discussed later.

(iv) One of the FTC's contentions is that comparative advertising provides more information and more useful information to consumers, thereby enabling them to evaluate products more effectively. Unfortunately, research to date does not seem to support this contention. Studies have generally found no significant differences between comparative and noncomparative advertising in terms of information quantity or perceived usefulness (Wilson, 1976, Pride et al., 1977, McDougall, 1977, Shimp and Dyer, 1978, Golden, 1979). However, the failure to find a significant relationship with respect to informativeness of comparative advertising could represent a methodological bias since all of the studies cited above tested only low-involvement products.

(v) In terms of comprehension and identification, comparative advertising does not significantly outperform noncomparative advertising (Ogilvy & Mather, 1976/77) even though more correct sponsor identification was recorded for durable goods.

The findings on the cognitive component in relation to comparative advertising suggest that the advertising message recipients may adopt different strategies when processing comparative and noncomparative messages. For example, consumer disdain for the use of brand comparisons and skepticism toward advertisers who use them have been revealed in several studies (Golden, 1979; Shimp and Dyer, 1978; Wilson, 1976). Dislike for advertisements that make explicit brand comparisons may motivate recipients to rely more on disparagement of the advertiser as a strategy for processing comparative \ messages than on their evaluation of message arguments (Belch, 1981).

Affective Component The affective component relates to the intensity and i direction of the consumer's feelings toward the 0 "totality of components" contained in the comparative advertisement. So far, very little research has been done in this area. Four aspects of the affective component that have been researched to date are:

(a) Specific Advertisement Attributes - where comparative advertising was found to be more offensive but more interesting (Wilson, 1976; Shimp & Dyer, 1978), and where the use of appropriate themes in the advertisements would increase their effectiveness (Golden. 1979);

(b) Products - where consumers indicated a greater willingness to change their views toward the product when exposed to comparative versus noncomparative advertising (Wilson, 1976);

(c) Sponsoring Company - where sponsoring companies of comparative advertising were viewed as less trustworthy (Wilson, 1976; Shimp & Dyer, 1978); and

(d) Comparative Advertising Practice - where McDougall (1977) documented weak support on consumer's attitudes toward comparative advertising.

In a more recent study (Goodwin and Etgar, 1980), it was concluded that comparative advertising is only marginally advantageous in improving consumers' feelings toward the advertisement presented. Apparently, it does not improve respondents' attitudes toward the promoted brand itself.

Conative Component This is the component that interests researchers trying to measure the effectiveness of comparative advertising. Three dimensions of measurement of this component have been researched:

(a) Buying Intentions None of the findings reported to date indicate any significant differences in buying intentions among consumers exposed to comparative advertising versus other types of advertising. (Golden, 1976; Shimp & Dyer, 1978; Golden, 1979; Belch, 1981).

(b) Brand Preferences The only evidence available from the Ogilvy & Mather (1926, 1977) study suggests that brand preferences are product-specific. There is no conclusive evidence that comparative advertising will generate greater brand preference.

(c) Purchase Behavior Again, the evidence provided by Ogilvy & Mather (1976, 1977) does suggest that comparative advertising may result in higher purchases. This result conflicts with the findings on buying intentions, and leads one to suspect that behavioral responses are product-specific.

The Situational Effects Model

The inconclusive findings on comparative advertising stemming from research based on the hierarchy of effects model has lead some researchers to believe that there

are key situational variables that impact on the communications effectiveness of comparative advertising. Figure 3 identifies some of the variables that have been explored in this line of research. They are discussed below:

Audience Characteristics The findings on audience characteristics indicate that

(a) Demographic profiles do not influence attitudes toward comparative advertising (McDougall, 1977). Also, personality variables do not seem to be related to the effectiveness of the different appeals generated through comparative versus noncomparative advertising (Goodwin & Etgar, 1980).

(b) Consumers who are reported users of the sponsoring brand tend to rank the message claims significantly more favorably than do users of competing brands or nonloyal users (McDougall, 1977).

(c) Prasad (1976) reported that perceived credibility ratings of product superiority claims made in a comparative advertisement were significantly lower among subjects who had a prior preference for the comparison brand than for subjects who did not have a prior preference for the competing brand. Other studies, however, have failed to indicate any differential effects or comparative advertisements on users or nonusers of the competing brand (Pride, et al., 1977; Belch, 1981).

Media Characteristics There is evidence in the literature that comparative advertising is relatively more effective in print media than in television. Belch (1981) for example, posits that print may be more effective than television as a medium for comparison advertising, especially for the two-sided appeal since a printed message allows the recipients greater opportunity to process the message stimulus and to assess the credibility or the advertiser who admits product inferiority on some attribute. This argument is based on the notion that information overload may occur when too much information has to be processed by the subject in a situation where exposure time is constrained, for example a television commercial.

FIGURE 3

THE SITUATIONAL EFFECTS MODEL

It is clear that the impact of media characteristics on the effectiveness of comparative advertising requires more research, particularly on the effects of multiple exposures and the performance of other media such as radio.

Message Characteristics Various components of the message itself have been found to affect comparative advertising:

(a) Pride, Lamb, and Pletcher (1977) found that a moderate level of intensity in terms of information content, is preferred by subjects over a high or low intensity.

(b) Uses of tests or studies to substantiate a claim depend on the credentials of the agencies cited. In general, substantiation of claims affects credibility and believability (Golden, 1979) and unsubstantiated claims in comparative advertising apparently have no advantage over noncomparative advertisements in terms of effectiveness (Wilson. 1976).

(c) In relation to specific themes, comparative advertisements have demonstrated a relatively stronger influence on purchase intentions than is the case for noncomparative advertisements (Golden, 1979).

(d) The effectiveness and credibility of comparative advertising can be significantly increased through the use of two-sided rather than one-sided claims (Swinyard, 1981). Moreover, it may be important to disclaim on more than one attribute if the effectiveness and credibility of the appeal are to be maximized (Belch, 1981).

Product/Company Characteristics

(a) Product/Services To date, research on comparative advertising has explored a variety of product categories including beer, deodorants, mouthwash (Wilson, 1976), pain relievers, health and beauty aids (Ogilvy & Mather, 1976 & 1977), toothpaste (Jain & Hackleman, 1978), fast foot chains (Shimp and Dyer, 1973), and grocery outlets (Swinyard, 1981).

(b) Durable Versus Non-Durable Products Virtually all of the studies so far have focused on low-involvement products. Little attention has been paid to high-involvement durable products (except Prasad's (1976) study on a fictitious camera and the Ogilvy & Mather (1976, 1977) research on consumer services.) Only one study (Jain and Hackleman, 1978) examined the effectiveness of comparative advertising across convenience, shopping and specialty goods. The authors concluded that convenience goods seem to be most conducive to comparative advertising. However, this study represents a single test of the effectiveness of comparative advertising across product classes. Further research is clearly needed before any conclusive statements can be made about the effectiveness of comparative advertising for different classes of consumer products.

(c) Market Position Golden (1979) found that for particular competitive positions, the theme employed by the advertiser may differentially affect the relative impact of a comparative advertisement. Shimp and Dyer (1978) conclude that comparative advertising is more effective for new market entrants whereas non-comparative advertising may be better for established sponsoring brands. Finally, Jain-and Hackleman (1978) contend that a market leader probably should not use comparative advertising for there are no apparent benefits to the firm in doing so.

IMPLICATIONS FOR ADVERTISERS

As the preceding summary of key research findings indicates, the expected benefits of comparative advertising frequently have failed to meet the test of empirical scrutiny. To date, the record of research on the topic suggests that comparative advertising may only prove differentially advantageous to an advertiser when certain conditions are met. If notching else, research on comparative advertising has shown that this particular message strategy produces complex, multidimensional effects and clearly indicates the need for further theoretical development in the area.

The diversity or research results on comparative advertising leaves advertisers and ad agency officials in a quandary. Is comparative advertising more effective than non-comparative advertising? How do comparative and non-comparative advertisements compare in terms of differential impact on awareness, believability, credibility, comprehension and advertiser identification? Do they differ with regard to effects on purchase intentions, brand preferences, purchase behavior? What are the effects of copy claim variation and substantiation on the performance of competitive advertisements? Is effectiveness influenced by factors such as prior brand loyalty or competitive position? Should companies use comparative advertisements and, if so, under what conditions?

Since research on comparative advertising is still rather young, any recommendations which are made to management ought to be treated as tentative guidelines rather than as definitive statements of message strategy. On the basis of the results of studies covered in this paper, some general observations about comparative advertising may be advanced:

The effectiveness of comparative advertising appears to be influenced considerably by situational factors. Decisions about employing comparative advertising ought to be made at the brand level taking into account brand loyalty, competitive market position and audience characteristics;

Comparative advertising may be more suitable for convenience goods than for high-involvement, durable products or consumer services. This observation is based on very little research and is, therefore, highly speculative;

Comparative advertising may be particularly effective for promoting new brands with strong product attributes;

Comparative advertising is likely to be more effective if its claims are substantiated by credible sources, e.g. an independent research organization and two-sided claims that inoculate the consumer against potential counter-arguments have greater impact than one-sided claims;

Comparative advertising may be used effectively to establish a brand's position or to upgrade its image by association;

Audience characteristics, especially the extent of brand loyalty associated with the sponsoring brand, should be considered in deciding on a comparative advertising strategy. Users or owners of the named competitor brands appear to be resistant to comparative claims;

Since people consider comparative advertisements to be more interesting than non-comparative advertisements (as well as being more "offensive"), these commercials may be effective if the product category is relatively static and non-comparative advertising has ceased to be effective;

Appropriate theme construction can significantly increase the overall effectiveness or comparative advertising;

It is important to ascertain how many product attributes to mention in a comparative advertisement. The number used should not be excessivelY high nor low

Print media appear to be better vehicles for comparative advertisements since print lends itself to more thorough comparisons, that is, the consumer has control over the time needed to process the additional information.

The preceding observations stem from a larger set of factors which influence the effectiveness of comparative advertising. These ideas are revealed in the model presented in Figure 4 which was developed as an aid to managerial decision-making.

OPPORTUNITIES FOR RESEARCH

Despite the research progress which has been achieved over the past few years, much more work needs to be done before solid conclusions may be drawn about the appropriateness of comparative advertising as a message strategy and about the types of factors which mediate its effectiveness. There are several areas which are urgently in need of additional research.

FIGURE 4

FACTORS INFLUENCING COMPARATIVE ADVERTISING

First, research examining the potential impact of multiple exposures on the subject are required to determine whether differences in comparative and non-comparative messages might occur as consumers experience more frequent exposures to the message. To date, only Belch's (1981) study has focused on multiple exposures of television commercials. Second, research might be undertaken to compare the relative effectiveness of television, print and radio for comparative advertising even though significant methodological problems might be encountered. The effects of using radio have never been studied and no previous studies have explored the effects of using multiple media for message delivery. Third, additional research is clearly required on high-involvement products (shopping and specialty goods) and consumer services. Comparative advertising is currently in widespread use in a number of durable product categories, e.g. automobiles. Fourth, other issues in the cognitive area deserve research attention. In particular, how does the consumer process comparative advertising messages? What strategies does he/she employ to cope with conflicting claims or information overload? What coping strategies are invoked? Finally. the impact of comparative versus non-comparative advertisements on consumers post-purchase evaluations of goods needs to be assessed. For example, does comparative advertising affect prior expectations and hence consumer satisfaction with the sponsored brand? These are just some of the dimensions of comparative advertising which constitute exciting research opportunities for marketing academics and practitioners.

REFERENCES

Belch, G.E. (1981), "An Examination of Comparative and Noncomparative Television Commercials: The Effects of Claim Variation and Repetition on Cognitive Response and Message Acceptance," Journal of Marketing Research, 18 (August), 333-49.

Bowen, I. and Chaffee, S.H. (1973), "Product Involvement and Pertinent Advertising Appeals," unpublished working paper, University of Wisconsin, October.

Della Bitta, Albert J., Rent B. Monroe and John M. McGinnis (1981), "Consumer Perceptions of Comparative Price Advertisements," Journal of Marketing Research, 18 (November), 416.

Etgar, M. and Goodwin, S.A. (19,7), "Comparative Advertising: Issues and Problems," in H. Keith Hunt (ed.), Advances in Consumer Research, Vol. V, Association for Consumer Research, 1978, 63-71.

Golden, Linda L. (1976), "Consumer Reactions to Comparative Advertising," Advances in Consumer Research, 3, Association for Consumer Research.

Golden, Linda L. (1979), "Consumer Reactions to Explicit Brand Comparisons in Advertisements,"Journal of Marketing Research, 16 (November), 517-32.

Goodwin, S.A. and Etgar, H. (1980), "An Experimental Investigation of Comparative Advertising: Impact of Message Appeal, Information Load, and Utility of Product Class," Journal of Marketing Research, 17 (May), 187-202.

Jain, Subhash C. and Hackleman, E.C. (1978), "How Effective is Comparison Advertising for Stimulating Brand Recall?" Journal of Advertising, 7 (Summer), 20-25.

Lavidge, R.J. and Steiner, G. (1961), "A Model of Predictive Measurements of Advertising Effectiveness," Journal of Marketing. 25 (October), 59-62.

Levine, Philip (1976),. "Commercials That Name Competing Brands," Journal of Advertising Research, 16 (December), 7-14.

Lincoln, D.J. and Samli, A.C. (1979), "Empirical Evidence of Comparative Advertising's Effects: A Review and Synthesis," AMA Educators Conference Proceedings, 367-370.

Mazis, M.B. (1976), "A Theoretical and Empirical Examination of Comparative Advertising," Faculty Working Paper, College of Business Administration, University of Florida.

McDougall, G.H.G. (1977), "The Strategy of Comparative Advertising," Working Paper Series No. 168, School of Business Administration, University of Western Ontario, January.

Ogilvy & Mather Research (1976): The Effects of Comparative Television Advertising That Names Competing Brands.

Ogilvy & Mather Research (1977): A Further Investigation Into the Effects of Comparative Television Advertising That Names Competing Brands.

Ogilvy & Mather Research (Fall 1977): An Investigation Into the Effects of Comparative Print Advertising That Names Competing Brands.

Prasad, V. Ranti (1976), "Communications Effectiveness of Comparative Advertising: A Laboratory Analysis," Journal of Marketing Research, 13 (May), 128-37.

Pride, W.M., Lamb, C.W. and Pletcher, B.A. (1977), "Are Comparative Advertisements More Informative for Owners of the Mentioned Competing Brand Than for Nonowners?" Proceedings, American Marketing Association Educators Conference. Hartford. Connecticut.

Sawyer, A.G. (1973), "The Effects of Repetition of Refutational and Supportive Advertising Appeals," Journal of Marketing Research, 10 (February), 22-33.

Sewall and Goldstein (1979), "The Comparative Price Advertising Controversy: Consumer Perceptions of Catalog Showroom Reference Prices," Journal of Marketing, 43 (Summer) 13-19.

Shimp, Terence A. and Dyer, D.C. (1978), "The Effects of Comparative Advertising Mediated by Market Position of Sponsoring Brand," Journal of Advertising, 3 (Summer) 13-19.

Smith, R.E. and Hunt, S.D. (1978), "Attributional Processes and Effects in Promotional Situations," Journal of Consumer Research, 5 (December), 149-58.

Swinyard, W.R. (1981), "The Interaction Between Comparative Advertising and Copy Claim Variation," Journal of Marketing Research, 18 (May), 175-86.

Webb, P.H. (1979), "Consumer Initial Processing in a Difficult Media Environment," Journal of Consumer Research, 6 (December), 225-36.

Wilkie, W.L. and Farris, P. (1975), "Comparison Advertising: Problems and Potential," Journal of Marketing, 39 (October), 7-15.

Wilson, R.D. (1976), "An Empirical Evaluation of Comparative Advertising Messages: Subjects' Responses on Perceptual Dimensions." Advances in Consumer Research, 3, Association for Consumer Research, 53-57.

Wilson, R.D. and Muderrisoglu, A. (1980), "An Analysis of Cognitive Responses to Comparative Advertising," in J. C. Olson, (ed.), Advances in Consumer Research, 7, San Francisco: Association for Consumer Research, 566-571.

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