Perceived efficacy. Attitude is highly related to one’s perceived efficacy as attitude is a part of cognitive process people go through. When the advertised products make claims about functions that help the customers to reach their goals, the perceived level of efficacy about weight loss should be viewed as critical. The importance of efficacy is well described by Bandura (1990) who stated that a sense of self-efficacy serves as a motivator for people that help initiating a life or habitual change. He argues that unless the action of behavior change seen as feasible, people don’t find such change worth trying.

In a context of advertising, a similar scenario can be predicted.  If consumers believe that they can lose weight with the help of the advertised products based on the claims made by the advertisers, the attitude toward the brand and purchase intentions are more likely be influenced by it. Bandura (1991) conceptualized that the level of self-efficacy determines one’s commitment to achieve their set goals and high self-efficacy makes individuals raise a standard for the goal and less resistant to challenge.  Bandura (1993) also added that while the individual with high level of self-efficacy tends to visualize more positive outcome of the future, the opposite is true for those with lower self-efficacy.

According to Bandura (1977), there are several dimensions to efficacy expectations. Four major sources of efficacy expectations include performance accomplishment, vicarious experience, verbal persuasion and emotional arousal. Vicarious experience where two types of modeling, live and symbolic modeling indicate the link between visual elements of advertising and consumers’ response toward the visual stimuli. Bandura suggested that when people observe what other people are doing (through live or symbolic modeling), the visual demonstration of others performing an act can help the people to believe that similar level of performance can be achieved as well.

Another aspect of self-efficacy can be explained by Roger’s (1983) Protection Motivation theory in link with fear appeal. The association between fear appeal and self-efficacy in advertising deals with the claim made by advertisers (Snipes, LaTour & Bliss, 1999). Snipes and his colleague believe that advertised product’s key features of eliminating the fear serves as a coping mechanism that the specific claims featured in the advertisements work as a selling point, “Buy this product and your fear will be gone.” It seems that consumers with varying levels of self-efficacy will be persuaded by the advertising claims that offer to remove the barriers they had. Snipe and his colleague pointed that self-efficacy can be interchangeable with the perception of a person’s ability and can be a single most important factor in a situation where perceived threat and fear is high or seemingly realistic. Aside from verbal claims made by advertisers, Bandura (1977) noted that one’s self-efficacy can be influenced by three factors including one’s experience regarding the product, vicarious experience and persuasion made verbally. In contrast, Hunt and Vitell (1986) argued that information provided in advertising is not sufficient to make change to one’s self-efficacy as only little information is included in the form of advertising.

In spite of the debate over advertising information and its role on self-efficacy, several studies suggest that the amount of given information influences individual’s belief about performing a certain task (Krätzig &Arbuthnott, 2006). In a similar vein, Maddux and Kleiman (2012) suggested that a visual testimonial often found in weight loss product advertising serves as a vicarious experience making people believe that a difficult task can be achieved using the advertised product. Individual’s perceived-self efficacy can be partly influenced by the difficulty of given task. In addition, the complexity of task is often determined by amount of information given, therefore, it is intuitive to assume that the complexity of information influences people’s assessment of their efficacy regarding the task. Taking Bandura (1977)’s argument that visual demonstration using a visual stimulus with symbolic meaning of accomplishment can affect one’s self efficacy and the extent to which he or she can perform the act, I propose the following hypotheses examining the impact of visual elements of weight loss product ads on perceived self-efficacy.

H2a: Visual complexity positively influences consumers’ self-efficacy toward weight loss.

H2b: Visual contrast positively influences consumers’ self-efficacy toward weight loss.

Perceived risk (severity). Janz and Becker (1984, p.2) defined perceived severity (risk) that “feelings concerning the seriousness of contracting an illness (or of leaving it untreated) also vary from person to person. This dimension includes evaluations of both medical/clinical consequences and possible social consequences”.  Individual’s perceived risk should be also examined if understanding how people process information and make a decision using the given information after seeing an ad is essential to a study. Bettman (1970) conducted a study that examined the models explaining how information is processed. He argued that despite the fact his model is not based on the product type specifically, it does show that there are subsets of cues that people pay attention when making a decision. In addition, Bettman stated that perceived risk is an important product cue that can be used to predict consumers’ decisions.  Using 12 product categories including Vitamins, Aspirin and Deodorants, Kaplan, Szybillo and Jacoby (1974) found that five elements can predict approximately 70% of variance in perceived risk when people consider buying products. Financial, psychological, performance, physical and social risks are the five components that are believed to predict the extent to which people perceive as risks (Jacoby &Kaplan, 1972; Kaplan, Szybillo & Jacoby, 1974).

One of the reasons for acknowledging risk is that warning label or information is not required by FDA or FTC in weight loss products advertised in magazine. However, the increasing number of advertisements with deceptive messages targeted to the audience who are vulnerable at the time of exposure suggests that inclusion of such information alerting customers of potential danger or risk seems beneficial. A study by Williams (1976) revealed that when a warning statement was provided in the advertisement, a higher level of perceived product risk was reported among customers. However, the reported effect did not last longer than a week from the initial exposure of the advertisement. Although the findings from literature are not universal suggesting further empirical studies are necessary to be conclusive, the impact of warning information in advertising seems worth investigating.

Several studies suggest that having concrete risk information in the advertising not only increased the level of fear but also increased the rate of recall suggesting that consumers can use the information to make a better choice (Smith, 1990). Literature suggests that the format of information being audio or audio-visual, amount of information and product type are some of a few factors that influence the perceived level of product risk (Morris, Ruffner & Klimberg, 1985; Morris, Masiz & Brinberg, 1989).  The concerns with diet pills or weight loss product advertised in print media are that advertisements featured in magazines are information intense. According to Nourse and Anderson (1973), consumers will not process or read every information cue as the relevance of each information varies especially when there is a lot of information. This can be partly explained by selective attention to the information and visual noticeability out of crowded information is a key for the information to be read. In that regards, Beltramini (1988) suggest that utilizing larger types and vivid color scheme can increase attention.  In sum, having more visual elements to provide relevant product information and more information intense and, in turn, increases the level of fear as visual demonstration of negative consequences as a result from not following the proposed behavior. While the inclusion of multiple visual images in an ad provides vivid and explicit representation of desired outcome, the images can also influence how consumers evaluate the risk involved with the product. Coupled with perceived self-efficacy, people may have a lowered level of risk about using the advertised product for weight loss because the visual images made them believe that weight loss is relative easy and quick without any risk involved as much of the images are positive (except for the before photo).  Given the possibility that having more relevant images that can induce the feeling of fear for some people while vivid image of outcome can decrease fear, the following hypothesis is proposed.

H3a: Visual complexity negatively influences consumers’ perceived risk of weight loss products.

Perceived risk is highly associated with consumers’ level of uncertainty as scholars suggested that it is one of two dimensions of perceived risk (Cox, 1967). Intuitively, people try to remove or lower the risk by controlling one or two elements of risks. One of the common way of lowering the risk is to lower the level of uncertainty and it can be achieved by obtaining more information (Taylor, 1974). In that regards, seeing photos of model with positive outcome of weight loss products can be used as additional piece of information, which in turn, can decrease the level of uncertainty. In a similar vein, Lin, Lu and Wu (2012) found that when used effectively, visual image can increase the quality of message and consequently decrease the level of uncertainty.

According to Mitchell (1999), one’s evaluation of negative consequences is what determines the level of perceived risk. He proposed a formula of measuring perceived risk by summing the importance of negative consequences and possibility of negative consequences. Applying this formula to the current study, the researcher can expect that consumers who see the before and after photos are more likely to reduce the uncertainty of outcome and the level of perceived risk is lower as the probability of negative consequences (being overweight or not being able to lose weight) can be reduced. Similarly, while the before photo can served to increase the fear, the after photo that is placed side by side can also be used to lower the perceived risk.  Therefore, the following hypothesis about the role of visual contrast in weight loss product ad on perceived risk is proposed.

H3b: Visual contrast negatively influences consumers’ perceived risk of weight loss products.

Trustworthiness of information. Advertising credibility varies by product (Liu & Poon, 2009). In that regards, the researchers also noted that weight loss products often contain deceptive content which, in turn, affects level of credibility. In their study with samples collected from Hong Kong, the researchers found that advertising with weight loss products received low credibility in comparisons to other types of products. The authors concluded the reason for lower credibility is due to the prevalent claims made in verbal form. Instead of providing information with statistical data that is perceived more credible, most advertising tested used verbal claim and many consumers believed that there was a higher likelihood of having deceptive messages in verbal claims than numerical claims (Mohr, Eroǧlu & Ellen, 1998).

In contrast, studies have shown that information quality or amount of information presented in advertisement affect whether people perceive the information trustworthy or not. According to Toma (2010), people with more textual information perceived that the information is more trustworthy while the presence of photography decreased the perception. The presence of graphics using certain color schemes or layout can influence the level of credibility or trustworthiness of information. David & Glore (2010) suggest that visual images have an essential role in affecting the perception of message and the credibility of information. Given the finding that more than one third of consumers tend to use visual presentation of websites to make judgment on credibility (Fogg et al., 2003), it is highly likely that visual elements in advertisements can also be used as cues for trustworthiness of given information. Lin, Lu and Wu (2012) also found the superiority effect of using visual images in perceived trustworthiness that more effective communication was observed using visual manipulations.

In sum, trustworthiness of information presented in advertisements is associated with information quality and the perceived information quality can be determined by the amount of provided information. The presence of verbal and visual information influence the amount of information quality as well as information quality. As the number of visual objects increases, visual complexity increases as well. Taking this rationale into consideration, I propose the following hypothesis.

H4a: Visual complexity positively influences information trustworthiness of weight loss product advertisements.

One of the main criticism toward many advertising promoting weight loss products is that pictures used in the ad can be quite deceiving. As discussed in the beginning of this paper, it is suggested that approximately 40% of weight loss product ads from 1985 to 2007 include at least one deceptive statement (Cawley, Avery & Eisenberg, 2011). Apart from verbal claims, deception often takes a form of visual display. As mentioned by Messaris (1997) about the danger of using pictures in advertisement to deceive consumers, photographs are used to serve an important role to persuade consumers luring people to believe that the pictures are accurate representations of feasible outcome even if there is a possibility that the images are digitally altered. If conscious consumers aware of the visual manipulation, information trustworthiness might be affected negatively. In contrast, for those who are less skeptical and not keen on the details, the pictures might be utilized as a source of information trustworthiness when evaluating the info. Taking the important role of visual contrast that vividly projects an image of ideal body next to the body that is less desired, but more relatable might influence consumers’ judgment of information trustworthiness. Therefore, the following hypothesis is proposed.

H4b: Visual contrast positively influences information trustworthiness of weight loss product advertisements.

Purchase intention. Many scholars refer to purchase intention as an indication of consumers’ behavior or responses to advertising that can be predicted and measured (Li, Daugherty & Biocca, 2002). The relationship between attitude toward brand and purchase intention have long been discussed by many scholars and the literature. Fishbein and Ajzen (1975) suggest that individual’s attitude toward product has a strong association with one’s belief about the object. As a result, the belief leads to an attitude toward the product and subsequently influence how an individual behaves regarding purchase decision.

Common practices of measuring purchase intention are to ask consumers the likelihood of buying the product after they saw an ad (Beerli & Santana, 1999) using four items with a seven-point semantic differential scales. A study by Bearden, Lichenstein and Teel (1984) used the scales using the items of unlikely/likely, improbable/probable, uncertain/certain and definitely not/definitely. In a similar vein, measures of purchase intention do not have much uniformity. Batra and Ray (1986) used a single item asking how likely people would buy the product by using “definitely would buy/definitely would not buy” scale. In contrast, MacKenzie and his collegues used three items using (likely/unlikely, probable/improbable, possible/impossible) for purchase intention. The same scales have been used in many advertising and marketing studies (Singh, Lessig, Kim, Gupta & Hocuttt, 2000). Another frequently used method of assessing purchase intention is using a single item asking how likely you would buy products you saw or from a specific company on a seven-point Likert scale (David, Kline & Dai, 2005).

The direction and degree to which visual components of advertisement influence consumers’ purchase intention are mixed. When both visual and verbal information were taken into consideration, it is suggested that only verbal information is believed to have any impact on purchase intention (Kim & Lennon, 2008). However, the researchers noted that the impact of visual cues was significant on purchase intention when perception of image size and verbal information were used rather than the actual size of picture and verbal information. In addition, several studies support the notion that the presence of pictures can positively influence consumers’ purchase intention. More specifically, Putrevu, Tan and Lord (2004) found that higher level of purchase intention was reported among females who have seen ads with higher level of visual complexity while no effect of verbal complexity was found.

Despite the conflicting findings, it is suggested that picture superiority led us to believe that inclusion of visual cues has opposite impact on attitude toward product (Paivio, 1970) and better recall (Starch, 1966; Shepard, 1967), which are antecedents of purchase intentions. Literature suggests that the two independent variables, visual complexity and visual contrast, have impact on attitude toward the product as well as the trustworthiness of information featured in the ad. As purchase intention is, though not always, derived from positive attitude toward the product and trustworthiness (Yoon, 2002), I propose the following two hypotheses examining the relationship between visual manipulation and purchase intention.

H5a: Visual complexity positively influences consumers’ purchase intention of weight loss products.

H5b: Visual contrast positively influences consumers’ purchase intention of weight loss products.

Proposed Model

Moderators

Characteristics of weight loss product users

Results of a national survey by Pillitteri and his colleagues (2008) revealed several characteristics of dietary supplement users. They found that approximately 34% of the respondents who made several attempts to lose weight have reported using a dietary supplement to achieve their weight loss goals. In terms of age, women, in their 20s and 30s are more likely to use dietary supplements. The results also indicated that prevalent usage was found among African American and Hispanics and people with lower education and income had a higher likelihood of using dietary supplements.  In their study, it is suggested that people with higher number of attempts to lose weight and with a goal of losing more than 25 pounds tend to use dietary supplements more.

Scholars suggested that one of the main reasons many Americans are induced by a quick solution such as diet pills and weight loss products, is that achieving weight loss requires changes in lifestyle and physical activities (Blanck, Khan & Serdula, 2001).  Most of the people who find such changes difficult and not feasible often turn to easy remedies by taking alternative medicines or dietary supplements with false claims.  In their study, Blanck and his colleagues found that approximately one third of respondents who used prescribed weight loss product users have reported of suing non-proscription products (Blanck, Khan & Serdula, 2001).  According to a report published by the National Institute of Health, losing 1 pound per week and lowering daily calorie daily consumption by 500 to 1,000 a day to lose 5% to 15% body weight is ideal and practical for long-term goal for weight loss (2002 FTC report).

Individual differences. A study by Putrevu, Tan and Lord (2004) revealed that there are three factors that influence the preference of visual complexity of advertising: need for cognition (NFC), knowledge, gender. Based on their classification on visual complexity (independent variable), their findings suggest that for those individuals who have higher ability to process cognitive structure of visual stimuli (high for NFC), more complex advertising was effective. In addition, one’s knowledge has a strong association with their evaluation of visually complex advertising.  Gender was another moderator of their study such that females showed higher tendency to prefer visually complex advertisement.

There is a consensus that there are individual differences as to how people process visual information. One of the few factors raised by literature is one’s ability to process information cognitively. A study by Cawley, Avery and Eisenberg (2011) suggested that the impact of weight loss product advertisement was greater for White females than African-American females while there was no difference between them regarding education and income level making ethnicity a stronger determinant of effectiveness of weight loss product ads. However, a study by Cawley, Avery and Eisenberg (2013) suggested that education plays an important role in discerning deceptive advertising that women with more education can combat deceptive advertising better and follow more healthier way of dieting.

According to Soley and Reid (1983), consumers’ characteristics including income and ethnicity influence one’s satisfaction with the information value of advertising in magazine and on TV. More specifically, they stated that while both blacks and whites were more satisfied with information given in magazine than on TV, a higher level of satisfaction was reported by blacks than whites for magazine. In regards with income level, people with middle income hold the highest satisfaction toward information provided in magazine than other income levels. However, the study failed to explain the rational as to why such results were observed leaving a room for future studies.

High/Low visualizers. When people are exposed to a piece of information, it is natural that some people visualize the information whether it is in verbal or visual forms.  Visualization can come in different forms. For example, people may attempt to visualize the outcome of trying a specific product or create an imagery of claims made in verbal forms.  Studies about individual’s difference in visualizing showed that one’s ability on memory performance is highly influenced by visualizing ability. More specifically, a study by Gur and Hilgard (1975) indicated that high visualizers were superior to low visualizers in matching two pictures faster. Although the distinction between low and high visualizers on words were not prominent, when information was given in forms of pictures, high visualizers performed much better even on long-term memory (McKelvie & Demers, 1979).

Visualizers can also be distinguished from non-visualizers or verbalizers.  The visualizer-verbalizer cognitive style can be defined as “individual preferences for attending to and processing visual versus verbal information (Jonassen & Grabowski, 1993, p.191). Taking the definitions, visualizers can be classified as people whose primary cues for information processing are images while verbalizers tend to use verbal information as primary information means (Kozhevnikov, Hegarty & Mayer, 2002). Since the current study focuses on visual deception, it is intuitive to believe that those who are visualizers who rely heavily on visual cues for information processing are more likely to be influenced by the study. Taken the rationale, I propose the following research question.

RQ1: To what extent, does one’s ability to visualize influence the impact of visual complexity and visual contrast on attitude toward product, self-efficacy, perceived risk, trustworthiness and purchase intention?

Gender differences. While similar strategies were utilized for both men and women when controlling body weight, women tend to try to lose weight at a lower BMI than men. More than 30 % of women with normal range of BMI have reported to attempt to lose weight (Serdula et al.,1999). In a study examining 1061 print magazines for weight loss products from 1985 and 2007, Cawley, Avery and Eisenbergs (2011) found that a far greater number of women (68.5%) has been exposed to advertisements for weight loss products than men (48.6%).  The results suggest that out of 647 magazines ads with 1061 time appearances, a little less than 50% of the ads could be identified as deceptive advertisements. A claim about rapid weight loss (e.g., lose 3lbs a week) was the most common form of deception. More interestingly, the study confirmed that exposure to the weight loss product had a huge impact on consumption such that the more people are exposure to the ad, the more likely they will consume weight loss products.

Although it is highly debatable, there is a common belief for women’s superiority in verbal skill and men’s superiority in nonverbal skill including spatial skills (Lee, 2000). Similarly, a study on gender difference toward the identical print advertisements, Putrevu (2004) suggested that there is a strong tendency of women preferring advertisements that are complex while men preferred simpler ads or ads featuring visuals that enhance verbal information. He noted that women showed more positive attitude toward the ads that include rich information in both verbal and visual while men were more attracted to the ads with less information focusing on only a few attributes of the products. As a result, his findings suggested that the execution style of the ad should be based on difference.

Scholars also suggest that men and women process the same visual stimuli differently. According to Cafferata and Tybout (1989), females tend to interpret stimuli with more creativity and emotional attachment toward the stimuli than males. In contrast, the focus of attention is different such that males pay more attention to the individual parts with objectivity whereas females focus on small details yet see the stimuli from a broad perspective. In their study, Baird, Wahlers and Cooper (2007) found that women are more likely to respond to the ads with stimuli that evoke emotion and they tend to remember the ad longer than men did. Given the fact that many of the weight loss products utilize or attempt to arouse emotion, women are at a greater risk of being manipulated by the messages and claims made by the weight loss products.

Studies show that weight gain and being over-weight are more prevalent in female population that male population (St. Jeor, 1993). According to Evans (2003), women tend to match (or pair) having thin bodies with other types of success or happiness. Considering advertisers utilize their audience’s belief and psychological needs, it is not surprising that more women’s magazines feature articles and advertisements related to physical appearance and beauty than men’s magazines (Bazzini, Pepper, Swofford & Cochran, 2015). In fact, Malkin et al. (1999) found that more than two-third of popular women’s magazines had covers that featured contents related to the physical appearance. Given the negative effect of such emphasis on one’s appearance, the level of satisfaction with their bodies tend to be particularly lower for younger females suggesting that they can form dissatisfaction about their bodies at early ages (Tiggemann, 2006). Through a few studies about portrayals and objectification of female bodies, it is apparent that women consistently get a greater social pressure to be thin and control their body weight while men are forced to maintain their masculinity as much as women do (Frederick, Fessler & Haselton, 2005).

Consumers or readers of popular magazines are exposed to several advertisements and articles about weight-loss products. The overwhelming information and advertisements about the product may cause confusion for consumers (Royne, Myers, Deitz & Fox, 2016). In addition, scholars suggest that many of the women who are exposed to the advertisements tend to be less critical toward the advertising claims about weight loss products (DeLorme, Huh, Reid & An, 2012).

Gender differences were found in the way each gender deals with deceptive advertising (Cawley, Avery & Eisenberg, 2013). More specifically, men were more susceptible to magazine ads such that exposure to an ad decreased the likelihood of dieting with exercise while women were more likely to be influenced by TV. This suggests that a number of visual cues presented in the ad that is varied by a medium might influence the impact of an ad. Considering there is a gender difference when processing visual information, the following research question is proposed.

RQ2: To what extent, does gender influence the impact of visual complexity and visual contrast on attitude toward product, self-efficacy, perceived risk, trustworthiness and purchase intention?

Users/Non-users: Studies indicate that one’s attitude toward products can be influenced by past experiences. Whether the experiences were positive or negative or non-existent, there is a clear distinction between users and non-users of the products. For instance, Pillitteri et al. (2008) found that users of non-prescription dietary supplements are more likely have reported to use greater number of weight loss products than non-users indicating that possible susceptibility to weight loss products of users. As consumers’ experience of using dietary supplement can potentially alter their perception toward products and information about the specific product, the following research question is proposed to evaluate the moderating role of user experience.

RQ3: To what extent, does user experience influence the impact of visual complexity and visual contrast on attitude toward product, self-efficacy, perceived risk, trustworthiness and purchase intention?

Product Involvement. To understand consumers’ behavior, it is important to acknowledge that people are attached to products for different reasons (O’Class, 2000). The varying degrees of attachment can be best explained by the concept, “involvement”. The role of involvement in consumers’ behavior has been studied in the realm of media exposure and advertising messages (Park & Mittal, 1985; Mittal & Lee, 1989). A variety of conceptual definitions of involvement is available. For example, Greenwald and Leavitt (1984) suggested that when involvement is high, it refers to high personal relevance or importance while Mittal (1983) defined it as the one’s state of mind that determines the level of interest in a product. Since the conceptual definitions mentioned above are general, it is essential to make a distinction with product involvement and purchase involvement, two types of involvement. According to O’Class, product involvement is strictly related to product while purchase involvement is highly associated with the selection of brand. More specifically, product involvement is derived from consumers’ perception toward the product of interest. If consumers find the products that satisfy their needs and values, the level of product involvement is high and vice versa. In contrast, one’s effort and deliberation of brand selection determines the level of purchase involvement.

The literature supports a need for a clear distinction between product involvement and purchase involvement as they often occur separately or one can occur with the absence of the other (Mittal, 1989; O’Class, 2000). In addition, Mittal and O’Class noted that the relationship between the two involvements that usually product involvements occurs before purchase involvement making product involvement an antecedent. It is suggested that involvement can have important roles in many consumer behavior including interest in advertising and purchase behavior (Mittal 1983 and 1989; O’Class, 2000). The impact of two involvements, product and brand involvement can vary depending on the type of thought process required. For instance, the products that require more deliberation for purchasing or extensive though process (O’Class, 2000). The thought process to trigger interest in advertising message, however, is more influenced by product involvement. A theoretical framework that is pertinent to the relationship between involvement and consumer behavior is the elaboration likelihood model (ELM). Guided by literature and the assumption that personal relevance to product can influence how products in advertisements can be evaluated, I propose the following question.

RQ4: To what extent, does product involvement influence the impact of visual complexity and visual contrast on attitude toward product, self-efficacy, perceived risk, trustworthiness and purchase intention?

Self-perception of body image. One’s perception of being overweight or needing to control body weight can be affected by a few factors. Studies suggested that depending on individual’s socioeconomic status and demographic characteristics, the extent to which people perceive their weight can vary (Chang & Christakis, 2003; Paeratakul, White, Williamson, Ryan & Bray, 2002). More specifically, the results from Paeratakul et al. (2002)’s study showed that while there is prevalence among Americans with inaccurate perception of their weight status, white females had a higher tendency to perceive themselves being overweight. The authors added that perception of being overweight even if people are within normal BMI can lead to develop negative behaviors such as extreme dieting and eating disorders. Since many of the respondents in this study are more likely white females, it is likely that their perception of body image and appropriate weight can influence their evaluation of ad. Therefore, the following question is proposed to investigate the possibility of such relationship. One’s perception toward body image is highly associated perception. Hence, visual perception derived from visual complexity and visual contrast can be moderated by individual’s perception of their body image. The following research question sheds lights on the possibility.

RQ5: To what extent, does self-perception of body image influence the impact of visual complexity and visual contrast on attitude toward product, self-efficacy, perceived risk, trustworthiness and purchase intention?

Methodology

Sample

It is suggested that younger audiences such as college students are often targeted for weight loss products as they are believed to be less resilient (Ogden et al., 2006). Moreover, it is suggested that there is prevalence of body dissatisfaction among female college students making young female audience more desirable for advertisers (Rozin, Bauer & Catanese, 2003). Studies support a link between vulnerable college students who suffer eating disorders and higher probability of using dietary supplements (Celio et al., 2006).  Consequently, the current study attempts to compare two sets of different respondents comprised of students and adults who represent vulnerable audience of young generation age between 18 and 45.

200 respondents will be collected from a Southeastern university using student study pool, SONA system with a link of Qualtrics. Students will voluntarily participate in the study with an exchange of a class credit. Each student will be assigned with a unique ID and he or she will be directed to one of the experimental design. Equal number of samples will be allocated in one of the experimental design. Another sample of 200 respondents will be recruited and collected using a site called MTurk, service provided by Amazon for representative samples of public.

According to Buhrmester, Kwang and Gosling (2011), MTurk provides respondents that are diverse and more representative than student samples. The quality has proven to be sufficient to meet academic standard and the researchers expect an increasing popularity of MTuk among social science scholars in the future. Several sample qualifications will be added to test the study hypotheses including age, gender and their experience regarding weight loss products and their ability to visualize. Identical number or respondents will be assigned to each cell. Both sets of samples will be direct to the same experiment link that will collect data and upload it to Qualtrics. The study will take approximately 20 minutes to complete.

Pre-test (Pilot test)

The purpose of pre/pilot test is to establish reliability of stimuli used in the study.  In other words, it is essential that the stimuli are designed with an appropriate level of distinction among nine advertisements. A power analysis using G*Power shows that a minimum of 158 respondents will be required suggesting a little less than 20 respondents per stimulus. Taking the possibility of missing and invalid data, the researcher aims to collect from 180 respondents for the pilot test. As suggested, 6 different stimuli that will be used in the current study are included for pre-testing. The researcher will closely examine the responses to assess if the stimuli with low visual complexity vs. high visual complexity and low visual contrast vs. high visual contrast are constructed properly. Any failure to achieve an adequate level of reliability for the stimuli will result a revision to the stimuli until they reach the satisfactory level. Once the stimuli are proven to be valid, a comprehensive experiment will be conducted.

Since there are three elements in visual complexity including, color, a number of visual objects and symmetry, the following items were used and respondents were asked if they agree with the adjective based on the stimulus they are seeing. Some of the items were adapted from a study by Lavie and Tractinsky (2004). All items were measured using a five point Likert scale: Please indicate your opinion toward the following adjectives after seeing the ad.

• Colorful
• Complex
• Simple (reverse coded for complex)
• Symmetrical
• Organized
• Nicely Arranged
• Dull (reverse coded for colorful)

The scores obtained from sample will be added and averaged. Any scores above the average will be grouped as high and below the average will be classified as low. If the stimulus in the low visual complexity is scored lower than the one in high complex group and the difference is statistically significant (p<.05), the researcher will conclude that the reliability has been achieved. For visual contrast, the researcher is interested in finding out if respondents will identify the presence/absence of before/after photo. In addition, the visual manipulation maneuvered using Photoshop will be assessed by asking the following question. To make sure that the audience see the different amount of weight loss from the pictures before the experiment, the ad claim showing a specific amount of weight loss will be omitted asking people to guess the estimated weight loss.  In theory, if people find the weight loss from 32 lbs. weight loss stimuli (as the researcher designed) is more drastic than the ones in 15 lbs. weight loss stimuli and the difference is statistically significant, we can conclude that the manipulation is valid and adequate reliability is established.

Measurements

Manipulation check

One of the most important steps in this study is to acquire an adequate level of reliability on visual stimuli so that the researcher conducts a study using valid stimuli. The researcher set a list of questions asking people about the visual manipulation implemented in the stimuli. The main questions for the manipulation check, therefore, are based on visual complexity and visual contrast, the two independent variables. Cohen’s alpha of .80 or higher will be considered adequate and statistically significant result is expected from each of nine stimuli so that the respondents can recognize the difference in the level of visual manipulation. The level of visual complexity (three levels) and visual contrast (two levels) should be distinguished by the respondents as well. To estimate the visual complexity, three separate measures of color, layout and the number of visual objects were used to gauge the level of visual complexity. By summing the three measurements, the researcher can determine if the manipulation was valid.

Independent variables

Visual complexity

Unlike other retail products that were used in the studies of visual complexity, advertisements for weight loss products are developed and executed differently. It is rare to see the ads using illustration or using white empty spaces with an abstract image in this product category. Therefore, the current study has 9 stimuli that feature at least one visual object in ad. Out of six principles of visual complexity used in the study by Pieters, Wedel and Batra (2010), the current study uses three principles taken specifically from elements the authors call “design complexity”. The three elements are the number of visual objects, number of colors used and arrangement (layout of visual objects). Visual objects used here are a combination of a set of before/after photos (counted for two), an image of product and images relevant to product (natural plants/fruits). Visual complexity is categorized into three levels: high, moderate and low.

Visual contrast

Visual contrast is defined by a presence of a before/after photos and its level of contrast made on the model. Visual contrast is divided into two levels: high and moderate. The condition with high visual contrast will depict a set of before/after photos showing a model with a drastic weight loss (32lbs weight loss). The moderate visual contrast will feature a model with a moderate weight loss (less than 15lbs). Photoshop will be used to reflect the different amount of weight loss for visual contrast.

Dependent variables

Perceived efficacy: Three statements adapted and modified from Cox, Cox and Mantel (2010) to reflect the type of product being used in this study. “This diet pill is effective in losing weight,” “This diet pill works in losing weight,” and “People who use this diet pill are more likely to lose weight.” All statements were measured using a five-point Likert scale.

Perceived risk:  Perceived risk is measured using one statement asking respondents to rate on the following statement using a five-point Likert scale: Overall, this product is risky (Cox, Cox & Mantel, 2010).

Trustworthiness: Trustworthiness has many dimensions ranging from how much a person trust endorsers (source credibility) or how credible the message argument is (argument quality). As Ohanian (1990) suggested that source credibility can be comprised of attractiveness, trustworthiness and expertise. However, in this study, the researcher is interested in whether the visual manipulation has any impact on perceived level of trustworthiness based on the presence of model and/or their visual appearance. Because there are conditions with no human models, but all nine conditions feature the same verbal message, trustworthiness or credibility of message quality is used to determine the perceived level of trustworthiness. For this variable, five semantic differential scale items using a seven-point scale (Dependable/undependable, honest/dishonest, reliable/unreliable, sincere/insincere, trustworthy-untrustworthy) from Ohanian (1990) were used to measure the variable.  The five items would be added and the mean scores will be used to evaluate trustworthiness.

Attitude toward product:  The measurement used to assess attitude toward product is adapted from Cox, Cox and Zimmer (2006). The following four statements were asked using a five -point Likert scale. “Overall, I think this product is a very good product,” Using this product would be important to me,” People who use this product will lose weight more safely than those who do not. I would rather use this product than any currently available alternative”. The combined mean score from the four statements will be used for data analysis.

Purchase intention: Purchase intention is measured using a five-point Likert scale with a statement asking respondents how likely they will purchase the advertised product.

Moderating variables

Individual differences: A series of questions regarding individual differences were asked in the questionnaire. A list of questionnaires asking people’s demographics including age, gender, ethnicity, household income, education along with their knowledge toward weight loss product and dieting were included in the questionnaire.

High/Low visualizers: It is suggested that the original work of Visualizer-Verbalizer Questionnaire (VVQ) developed by Richardson (1977) is derived from Paivio’s (1971) study examining ways of thinking by using 86 items (Kirby, Moore & Schofield, 1988). Later, Kirby and his colleagues (1988) further developed a Visualizer-Verbalizer Learning Style, which was used in this study. Their study used 30 items including dream items. However, since the current study is only interested in distinguishing respondents into two groups based on their preference/ability of information learning and processing style, 20 items excluding dream items were used.  The following is the list of items used in the questionnaire with minor adjustment to wordings that fit better for the current study. The study by Kirby and his colleague used a true for false item to evaluate the statement. However, as suggested by (Mendelson & Thorson, 2004), having a five point Likert scale should provide more accurate estimation of respondents’ visualizing ability. After the respondents complete the statements, scores are collected and used to determine if the individual is visualizer or verbalizer based on the mean score of 10 items. The individuals with higher mean scores are classified as visualizers.

Verbal items

1) I enjoy doing work that requires the use of words.

2) I enjoy learning new words.

3) I can easily think of synonyms for words.

4)  I read rather slowly.

5) I prefer to read instructions about how to do something rather than have someone show me.

6) I have better than average fluency in using words.

7) I spend little time attempting to increase my vocabulary.

8) I dislike word games like crossword puzzles.

9) I dislike looking words up in dictionaries.

10) I have a hard time remembering the words to songs.

Visual items

11) I don’ believe that anyone can think in terms of mental pictures.

12) I find illustrations or diagrams help me when I am reading.

13) I have a hard time making a “mental picture” of a place that I have only been to a few times.

14) I seldom use diagrams to explain things.

15) I like newspaper articles that have photos/pictures.

16) I don’t like maps or diagrams in books.

17) When I read books with maps in them, I refer to the maps a lot.

18) The old saying, “A picture is worth a thousand words” is certainly true for me.

19) I have always disliked jigsaw puzzles.

20) I find maps helpful in finding my way around a new city.

In this study, a high visualizer refers to someone who scores high on visual items while those who score high on verbal items refers to low visualizers (verbalizers). The 20 items are randomly listed to avoid any bias associated with order. While the current study uses the scale borrowed from the study by Kirby and his colleague, a five point Likert scale will be used instead of True or False chose as more accurate information can be achieved from the Liker Scale (Mendelson & Thorson, 2004). There are 20 statements that are characteristics of visualizers and verbalizers. Of 10 statements, a half of the statements are phrased in a reverse coding to avoid any error associated with positively worded statement. When the researcher analyzes the data, the negatively phrased statements will be coded reversely. After the respondents complete the statements, scores are collected and used to determine if the individual is visualizer or verbalizer based on the mean score of 10 items.

Product Involvement: In their study, Chen and Tsai (2008) using 10 items to measure product involvement. Since some of the items were worded slightly differently, but used very similarly, five items were selected and used in this study. The five items using semantic differential scale are: irrelevant-relevant, unimportant/important, uninterested-interested, unappealing-appealing, not need-needed. The scores collected from the five statements will be added together for a mean score.

Self-perception:  A single question asking respondents of their perception toward their body weight was used to measure self-perception. The respondents are given three choices of overweight, normal and underweight (Chang & Christakis, 2003). Although a specific BMI based on statistics and medical experts for the classification could be given, the purpose of this question is to estimate the perception of their body image not the accuracy.

Methodology

Sample

As discussed earlier from the pilot test, the researcher aims to recruit 180 respondents for a pilot test that will validate a reliability and validity of visual stimuli. An actual study using the visual stimuli that are proven to be valid be carried out subsequently. The researcher will be recruiting the 180 respondents for the pilot test using MTurk as G*Power analysis for adequate sample size indicates that 180 people are required for the pilot test when a desired effect size of 0.25 and the power of 0.8 are used for calculation. If the pilot test shows the visual stimuli were valid, the actual study will be initiated. If the stimuli require revisions due to a lack of validity, a second pilot test will be followed after revision using the student participant pool provided by the department of Communication and Information Science at the University of Alabama.  Once the researcher acquires valid visual stimuli, the actual study will be conducted. The researcher aims to recruit a total of 200 respondents for the actual study, as suggested by G*Power analysis for the sample size.

Since both pilot and actual test aim to collect the respondents above the minimum requirement, the suggested sample sizes should be adequate. The students who will be participating in the pilot test will be recruited using a student research pool, SONA, a system designed for the students who registered certain courses at the department of Communication and Information Sciences at the University of Alabama. The students who patriciate in the study will be given an extra credit of 0.5 as a compensation. Although the pilot test will be conducted using a student pool, MTurk, a pool that will be used for the extended study will be consisted of adults 19 to 60 with diversity in age, education, and ethnicity. Since the current study have nine stimuli with varying levels of visual manipulation, identical number of respondents will be randomly assigned to one of the nine conditions.

Based on the study design, 3×2 cells, 6 different print advertisements were created using Adobe Photoshop and InDesign software. By using a fictitious product, XeroFat with visual variations only, each advertisement features an image of a bottle of product. To distinguish the level of visual complexity and visual contrast, the following guideline was used to create the advertisements. To measure the effect of visual manipulation implemented by advertisers and test if consumers can identify the congruence of visual stimuli and verbal claim meaning visual deception is identified, the researcher used Photoshop to make changes to the before photo. For example, the headline (body copy) states that the model in the photo lost 32 lbs. using the advertised product. While one of the stimuli shows the model with 32 lbs. weight loss, the other stimuli features an identical photo of after but a different before photo that has been retouched to show an image of a less significant weight loss. To make the difference noticeable, the original photography has been revised with an intention of looking less drastic (approximately 15 lbs. of weight loss). The key point here is to see if consumers are aware of such manipulation or if they automatically think or believe that 32 lbs. weight loss was achieved even after the visual manipulation. Therefore, the ability to identify the seemingly noticeable difference will help us to determine if such visual deception is maneuvered as it is intended. Specific details of visual manipulation are listed in appendix. In addition, the following detail of classifying the stimuli is as followed.

High complexity

1. Number of objects: 2 images (before/after), one product, three product relevant images: 6 images
2. Color: 3+
3. Arrangement: Asymmetry for before and after, product, non-product images

Moderate complexity

1. Number of objects: 2 images (before/after), one product, one product relevant image (natural fruits or plants): 4 images
2. Color: 2+
3. Arrangement: Asymmetry with product and before/after photos (before/after photos are symmetry)

Low complexity

1. Number of objects: one (product) +one non-product image (fruit or plant): 2
2. Color: white background
3. Arrangement: symmetry

High Contrast: 1 sets of extreme before/after photos

Moderate contrast: 1 sets of less extreme before/after photos

There are several reasons as to why pink and blue are used for the stimuli of moderate and high complexity. Despite a general belief about pink being gender specific, it is suggested that less than 10% of respondents in a study rated pink as their favorite color (reference). Since the current study does not take one’s predisposed color preference into consideration and their preference can affect their evaluation of advertising and the product featured in the ad, choosing a color that is as popular as other colors might avoid color bias. To secure consistency in colors used in model and background colors, the model is wearing a bikini in pink as well (the shade is a slightly different). In order to create high and moderate level of contrast among stimuli in terms of color, pastel blue (a color resulted from mixing blue and white) was chosen given the fact that color red is a typical warm color and pink is produced by mixing red and white. One of the most popular cool color is blue and having one color scheme from warm color while adding another color from cool color range will create some levels of contrast. In that sense, white background is chosen to create low contrast.

To ensure that the respondents pay enough attention to the visual stimuli without skipping and avoid risk of forced attention, the assigned stimuli will appear on the screen with the questionnaire (after demographic /pre-exposure questionnaire). Although the presence of stimuli on the screen may defeat the purpose of selective attention of the ad, it is reasonable to believe that similar behavior can be observed for magazine readers where they often flip back and forth for certain information when reading magazines.

Procedure

Both the pilot test and actual study will be created as an online experiment using Qualtrics. The web address will be linked to CIS student pool for students to participate and a link to Qualtrics page will be provided for people from MTurk. The data will be collected automatically and the researcher will be notified when the data collections are finished. After the data collection for the pilot test is completed, an analysis will be followed to determine the validity and reliability of the stimuli used in the pilot test. Once the researcher confirms that stimuli are adequate to be used in the actual study, the actual study on MTurk will be initiated. After data collection from MTurk is finished, the data will be sorted and analyzed for data analysis.

Stimuli

Statistical analysis

Identifying the relationships between the independent variables and dependent variables that have more than two levels along with having a few variables comprising moderating variables requires a series of 3X2 ANOVA (Factorial analysis).  Using a software called, GPower, a power analysis was conducted for an adequate sample size. Taking into the number of groups compared and a desired power of .80 and the effect size of .025, it is suggested that an adequate sample size is 158. Since the current study is aiming to collect 180 samples for a pilot test and 200 samples for the actual study, the sample sizes from both studies consider to be sufficient.