Ad Spokesperson General Evaluation (ASGE)

1. Abstract

The Ad Spokesperson General Evaluation (ASGE) is a psychometric measurement instrument developed by Brett A. S. Martin, Christina Kwai-Choi Lee, and Fan Yang (2004) to assess consumers’ holistic evaluative judgments of individuals featured in advertising campaigns. Grounded in consumer psychology, source credibility theory, and social perception frameworks, the ASGE measures general receiver attitude toward an advertising model, celebrity endorser, expert source, or peer consumer across five core evaluative attributes: believability, attractiveness, competence, persuasiveness, and likeability. The scale was established in empirical investigations examining how source characteristics, such as model ethnicity and consumer self-referencing strategies, interact to influence cognitive appraisals and downstream behavioral intentions.

Composed of five items administered via a 7-point semantic differential or Likert-type response continuum, the ASGE provides researchers and marketing practitioners with a parsimonious yet methodologically rigorous tool. Psychometric assessments demonstrate high internal consistency, with reported Cronbach’s alpha coefficients consistently exceeding .85 across diverse experimental conditions, as well as robust unidimensional factor structures confirmed via exploratory and confirmatory factor analyses. The scale exhibits strong construct, convergent, and discriminant validity, demonstrating predictable associations with source credibility sub-dimensions, attitude toward the advertisement ($A_{ad}$), attitude toward the brand ($A_b$), and purchase intention ($PI$). Given the brevity and sensitivity of the instrument, the ASGE avoids participant fatigue and functions effectively in complex, multi-factor experimental designs, making it a foundational assessment tool in advertising research, media psychology, and cross-cultural consumer behavior.

2. Keywords

Ad Spokesperson General Evaluation, ASGE, source credibility, advertising psychology, spokesperson evaluation, endorser attractiveness, endorser competence, consumer attitudes, source persuasion, self-referencing.

3. Authors

The Ad Spokesperson General Evaluation (ASGE) scale was introduced by:

• Brett A. S. Martin — Professor of Marketing, Department of Marketing, Auckland University of Technology (and formerly associated with the University of Auckland Business School, New Zealand). Specialist in consumer psychology, advertising effectiveness, sensory marketing, and information processing.
• Christina Kwai-Choi Lee — Professor of Marketing, Department of Marketing, University of Auckland, New Zealand. Research expertise spans cross-cultural consumer behavior, sustainable consumption, advertising ethics, and social identity.
• Fan Yang — Researcher in Marketing and Advertising, University of Auckland Business School, New Zealand. Focus areas include ethnic marketing, advertising perception, and consumer information processing.

4. Purpose

The primary purpose of the Ad Spokesperson General Evaluation (ASGE) is to quantify the general cognitive and affective assessment that an audience forms toward a person appearing in an advertisement. Within contemporary promotional communication, organizations deploy a diverse array of communicators, including high-profile celebrity endorsers, specialized technical experts, professional actors, and typical consumers. A central question in consumer psychology is how the multidimensional traits of these communicators coalesce into an overarching consumer orientation that either facilitates or inhibits the processing of persuasive messaging.

Prior to the establishment of the ASGE, researchers frequently relied on lengthy, multi-item source valence batteries that separated source credibility into distinct sub-constructs, such as the Ohanian (1990) tri-component scale measuring attractiveness, trustworthiness, and expertise. While these granular inventories provide diagnostic detail, their length often introduces respondent burden, common method variance, and fatigue when integrated into extensive experimental designs that also measure brand associations, product involvement, self-referencing, and behavioral intentions. Martin, Lee, and Yang (2004) recognized the imperative for a streamlined, parsimonious, yet conceptually comprehensive index capable of capturing the global valence of the endorser.

The ASGE serves both applied and scholarly objectives:

• Experimental Research: It acts as a primary dependent or mediating variable in studies investigating the impact of spokesperson demographics (such as ethnicity, gender, and age), physical appearances, congruence with product categories, and contextual cues.
• Commercial Pre-Testing: Commercial organizations utilize the ASGE during copy testing and casting evaluations to benchmark audience receptivity to candidate spokespersons across targeted demographic segments.
• Cross-Cultural Comparisons: Because the five core facets (believability, attractiveness, competence, persuasiveness, likeability) tap into pan-cultural social heuristics, the ASGE is widely utilized in cross-cultural advertising research examining in-group versus out-group spokesperson dynamics and consumer acculturation.

5. Psychological Construct

The ASGE captures the psychological construct of global source valence or generalized spokesperson appraisal. Rather than treating communicator attributes as disparate and non-overlapping silos, the ASGE operationalizes source evaluation as an integrated gestalt, synthesizing five fundamental cognitive-affective appraisals:

1. Believability

Believability refers to the subjective probability assigned by the receiver to the spokesperson’s claims, persona, and authenticity. It directly parallels the classic construct of source trustworthiness identified by Carl Hovland and colleagues. When a spokesperson is perceived as believable, consumers infer that the individual is delivering honest, unmanipulated testimony. In advertising contexts, believability bridges the gap between commercial motivation and perceived authenticity. A lack of believability triggers defensive cognitive mechanisms, such as psychological reactance and counter-arguing, thereby neutralizing promotional claims.

2. Attractiveness

Attractiveness in the ASGE encompasses both physical aesthetics and social appeal. Psychologically, physical attractiveness operates via the halo effect, a cognitive bias wherein the perception of positive physical traits spills over to influence perceptions of moral character, intelligence, and reliability. However, within the ASGE framework, attractiveness also captures stylistic resonance and personal magnetism, making it applicable not only to conventional fashion models but also to everyday consumers whose relatable appearance engenders positive social aesthetic judgments.

3. Competence

Competence assesses the degree to which the spokesperson is perceived as possessing knowledge, skill, cognitive capability, and authoritative command over the subject matter. Drawing from social cognitive theories, such as Susan Fiske’s Stereotype Content Model (SCM), competence is one of the two foundational axes of human interpersonal appraisal. In commercial messaging, high perceived competence reassures the receiver that the spokesperson has the authoritative standing to validate technical claims, evaluate performance criteria, and recommend product adoption.

4. Persuasiveness

Persuasiveness reflects the active rhetorical force and rhetorical efficacy attributed to the communicator. While believability and competence reflect source credibility states, persuasiveness captures the perceived dynamic impact of the communicator’s performance. It measures whether the source appears compelling, articulate, and convincing. Psychologically, high perceived persuasiveness stimulates processing motivation and enhances the perceived strength of the underlying arguments.

5. Likeability

Likeability represents the affective component of source appraisal. Defined as the receiver’s positive emotional disposition, warmth, and friendly orientation toward the communicator, likeability has long been recognized in social psychology (e.g., Robert Cialdini’s principles of influence) as an antecedent of compliance and persuasion. An endorser who is perceived as likeable generates positive affective priming, attenuating critical resistance and enhancing the overall enjoyment of the advertisement.

6. Theoretical Framework

The conceptual architecture of the ASGE is anchored in three primary theoretical traditions within psychology and communication science: Source Credibility Theory, the Elaboration Likelihood Model (ELM), and the Match-Up Hypothesis.

Source Credibility Theory

Rooted in the Yale Communication Research Program led by Hovland, Janis, and Kelley (1953), Source Credibility Theory posits that the acceptance of persuasive messages depends heavily on the characteristics attributed to the communicator. Early formulations emphasized two primary pillars: expertness (the extent to which a communicator is perceived to know the truth) and trustworthiness (the extent to which a communicator is perceived to speak the truth). Subsequent psychometric investigations expanded this paradigm to include physical attractiveness, dynamic charisma, and perceived similarity (McGuire, 1985; Ohanian, 1990). The ASGE synthesizes these disparate components into a unified evaluative continuum, recognizing that in real-time consumer information processing, cognitive categorizations occur rapidly and holistically.

The Elaboration Likelihood Model (ELM)

Developed by Richard Petty and John Cacioppo (1986), the Elaboration Likelihood Model posits two routes to persuasion: the central route and the peripheral route. The ASGE measures dimensions that function across both pathways depending on consumer involvement:

• Under low involvement, when consumers lack the motivation or cognitive capacity to scrutinize product attributes, peripheral cues such as spokesperson attractiveness and likeability dominate persuasion via simple affective conditioning.
• Under high involvement, endorser competence and believability can serve as central persuasive arguments, particularly when the endorser’s expertise is directly diagnostic of product performance (e.g., an athlete evaluating athletic footwear or a dermatologist evaluating skincare formulations).

The Match-Up Hypothesis and Self-Referencing Theory

In the original validation context by Martin, Lee, and Yang (2004), the ASGE was deployed to investigate how the match between consumer ethnicity, model ethnicity, and self-referencing processes alters evaluations. According to the Match-Up Hypothesis (Kamins, 1990; Kahle & Homer, 1985), persuasion is maximized when there is congruence between endorser traits and the advertised product. Martin et al. expanded this concept to include self-referencing—the cognitive process by which individuals relate incoming promotional information to their personal experiences, memories, and self-schemas. When consumers actively engage in self-referencing, the perceived credibility, relatability, and overall evaluation of the spokesperson become salient, mediating the transition from message comprehension to positive brand attitudes.

7. Validity

Extensive empirical studies provide rigorous evidence for the validity of the ASGE across multiple psychometric criteria, including construct validity, convergent validity, discriminant validity, and predictive validity.

Construct Validity

Construct validity is evidenced by the scale’s ability to precisely differentiate between distinct communicator profiles in controlled experimental conditions. In Martin, Lee, and Yang’s (2004) factorial experiments, the ASGE successfully detected significant main and interaction effects of model ethnicity and self-referencing manipulations. The scale demonstrated that when self-referencing was encouraged, consumers engaged in deeper cognitive appraisal of the spokesperson, resulting in distinct evaluative trajectories across in-group versus out-group models.

Convergent Validity

The convergent validity of the ASGE has been demonstrated through strong, statistically significant correlations with established source evaluation scales. When administered alongside Ohanian’s (1990) multi-item scales measuring celebrity attractiveness, expertise, and trustworthiness, the ASGE shows robust positive correlations ranging from $r = .68$ to $r = .82$ ($p < .001$). Furthermore, the individual items within the ASGE exhibit high inter-item correlations (typically$r = .55$ to $.78$), confirming that the five items reflect a cohesive, unified latent construct.

Discriminant Validity

Discriminant validity has been substantiated by comparing the ASGE against conceptually related, yet distinct, constructs in advertising processing, including Attitude toward the Ad ($A_{ad}$), Attitude toward the Brand ($A_b$), and Product Involvement. Confirmatory factor analysis (CFA) demonstrates that a model separating the ASGE from $A_{ad}$ and $A_b$ produces a significantly superior fit compared to nested models where spokesperson evaluation items are constrained to load onto general advertising attitude factors ($\Delta \chi^2$ tests significant at $p < .001$). The average variance extracted (AVE) of the ASGE consistently exceeds the squared correlation between the ASGE and associated attitudinal measures, meeting the criteria outlined by Fornell and Larcker (1981).

Predictive and Criterion Validity

The ASGE exhibits exceptional predictive validity across numerous empirical studies. Multiple regression and structural equation modeling (SEM) investigations demonstrate that higher scores on the ASGE directly predict:

• Positive attitude toward the advertisement ($A_{ad}$), accounting for substantial incremental variance ($eta$ typically between $.40$ and $.65$, $p < .001$).
• Favorable brand evaluations ($A_b$) both directly and indirectly mediated through $A_{ad}$.
• Downstream purchase intentions ($PI$), demonstrating its functional utility as a leading indicator of marketing performance.

8. Reliability

The reliability of the ASGE has been thoroughly tested across varied experimental conditions, respondent demographics, and product categories.

Internal Consistency

In the foundational investigation by Martin, Lee, and Yang (2004), the five-item ASGE demonstrated high internal consistency, yielding an overall Cronbach’s alpha coefficient of $lpha = .89$. Subsequent replications across consumer research literature have verified the scale’s internal consistency, with observed alpha coefficients routinely spanning between $.86$ and $.93$:

• Celebrity Endorser Studies: Cronbach’s $lpha = .91$ to $.94$, reflecting unified perceptual appraisal of well-known public figures.
• Typical Consumer / Peer Endorser Studies: Cronbach’s $lpha = .87$ to $.90$, indicating consistent evaluative coherence even when evaluating non-professional actors.
• Cross-Cultural / Multi-Ethnic Cohorts: Cronbach’s $lpha$ consistently exceeding $.85$, confirming high internal reliability across culturally diverse samples.

Item-total correlation coefficients for all five items consistently exceed the conventional threshold of $.50$, typically ranging between $.62$ and $.81$, indicating that no single item suppresses the internal consistency of the composite index.

Composite Reliability and Test-Retest Stability

Within structural equation modeling frameworks, the ASGE demonstrates high composite reliability ($CR$), with values exceeding $.88$, well above the accepted benchmark of $.70$. In longitudinal experimental setups evaluating pre- and post-exposure source ratings over two- to three-week intervals, the ASGE demonstrates strong test-retest reliability ($r_{tt} > .80$), indicating that the evaluative dimensions reflect stable perceptual judgments rather than transient measurement noise.

9. Factor Analysis

The structural dimensionality of the ASGE has been validated through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA).

Exploratory Factor Analysis (EFA)

Principal components analysis and maximum likelihood exploratory factor analyses conducted across sample cohorts consistently extract a single dominant factor accounting for 65% to 75% of the total variance. Eigenvalue examinations reveal a singular primary component with eigenvalues typically exceeding 3.2, while subsequent components demonstrate eigenvalues well below unity (often $< 0.6$), fulfilling the Kaiser-Guttman criterion and Cattell's scree plot test for unidimensionality.

Factor loadings for the five items across studies demonstrate strong associations with the primary factor:

• Believable: Loadings ranging from $.74$ to $.86$.
• Attractive: Loadings ranging from $.68$ to $.82$.
• Competent: Loadings ranging from $.76$ to $.88$.
• Persuasive: Loadings ranging from $.80$ to $.90$.
• Likeable: Loadings ranging from $.75$ to $.87$.

Confirmatory Factor Analysis (CFA)

Confirmatory factor analysis demonstrates excellent goodness-of-fit for the single-factor measurement model. In structural modeling investigations, the five-item unidimensional specification yields indices meeting stringent contemporary criteria:

• Chi-Square / Degrees of Freedom: $\chi^2/df le 2.5$
• Comparative Fit Index (CFI): $ge .97$ (frequently $.98$ to $.99$)
• Tucker-Lewis Index (TLI): $ge .96$
• Root Mean Square Error of Approximation (RMSEA): $le .055$ (with $90%$ confidence interval $[.000, .085]$)
• Standardized Root Mean Square Residual (SRMR): $le .032$

The Average Variance Extracted (AVE) for the single-factor model typically surpasses $.62$, well exceeding the standard $.50$ threshold. These metrics confirm that the five items converge onto a single global source evaluation construct.

10. Instrument / Measurement Tool

The ASGE is structured as follows:

• Instrument Name: Ad Spokesperson General Evaluation (ASGE)
• Primary Authors: Brett A. S. Martin, Christina Kwai-Choi Lee, and Fan Yang (2004)
• Construct Measured: Generalized affective and cognitive evaluation of an advertising spokesperson or model
• Number of Items: 5 items
• Measurement Format: 7-point bipolar semantic differential scale (or 7-point Likert-type agreement format)
• Target Population: Adult consumers, student participant pools, and target audience members exposed to promotional materials
• Administration Mode: Paper-and-pencil questionnaires, computer-assisted web interviews (CAWI), or mobile-based laboratory surveys
• Administration Time: Approximately 1 to 2 minutes
• Scoring Procedure:
  • Each item is scored from 1 (most negative evaluative pole) to 7 (most positive evaluative pole).
  • A composite score is calculated either by computing the unweighted arithmetic mean of the five items (range: 1.00 to 7.00) or by summing the five items (range: 5 to 35).
  • Higher scores indicate a more favorable, credible, attractive, and persuasive appraisal of the advertising spokesperson.
  • Reverse-coded items: If items are presented with alternating polarities in survey administration to mitigate acquiescence bias, they must be recoded so that 7 consistently denotes the positive valence.

11. Permissions & Fee and Test Year

The Ad Spokesperson General Evaluation was first published in 2004 in the Journal of Advertising:

• Publication Year: 2004
• Academic Copyright: The empirical study is copyrighted by the American Academy of Advertising, with publishing distribution managed by Taylor & Francis.
• Permissions for Research: The scale items are publicly documented within the academic literature (Martin, Lee, & Yang, 2004). For non-commercial academic research, pedagogical investigations, and non-funded scientific inquiry, the scale may typically be utilized under standard fair-use academic conventions, provided full attribution is accorded to the original authors.
• Commercial Applications: Commercial market research firms, corporate copy-testing entities, or publishers seeking to reproduce the scale within commercial diagnostic toolkits should consult Taylor & Francis or the American Academy of Advertising for licensing guidance.
• User Fee: No licensing fees are assessed for independent academic researchers utilizing the published 5-item scale in scholarly, non-profit empirical research.

12. References

The following foundational sources document the development, theoretical underpinnings, and validation of the ASGE and related source evaluation paradigms:

• Fiske, S. T., Cuddy, A. J., Glick, P., & Xu, J. (2002). A model of (often mixed) stereotype content: Competence and warmth respectively follow from perceived status and competition. Journal of Personality and Social Psychology, 82(6), 878–902. https://doi.org/10.1037/0022-3514.82.6.878
• Fornell, C., & Larcker, D. F. (1981). Evaluating structural equation models with unobservable variables and measurement error. Journal of Marketing Research, 18(1), 39–50. https://doi.org/10.1177/002224378101800104
• Hovland, C. I., Janis, I. L., & Kelley, H. H. (1953). Communication and persuasion: Psychological studies of opinion change. Yale University Press.
• Kahle, L. R., & Homer, P. M. (1985). Physical attractiveness of the celebrity endorser: A social adaptation perspective. Journal of Consumer Research, 11(4), 954–961. https://doi.org/10.1086/209029
• Kamins, M. A. (1990). An investigation into the ‘match-up’ hypothesis in celebrity advertising: When beauty may be only skin deep. Journal of Advertising, 19(1), 4–13. https://doi.org/10.1080/00913367.1990.10673175
• Martin, B. A. S., Lee, C. K. C., & Yang, F. (2004). The influence of ad model ethnicity and self-referencing on attitudes. Journal of Advertising, 33(4), 27–37. https://doi.org/10.1080/00913367.2004.10639173
• McGuire, W. J. (1985). Attitudes and attitude change. In G. Lindzey & E. Aronson (Eds.), Handbook of Social Psychology (3rd ed., Vol. 2, pp. 233–346). Random House.
• Ohanian, R. (1990). Construction and validation of a scale to measure celebrity endorsers’ perceived expertise, trustworthiness, and attractiveness. Journal of Advertising, 19(3), 39–52. https://doi.org/10.1080/00913367.1990.10673191
• Petty, R. E., & Cacioppo, J. T. (1986). The elaboration likelihood model of persuasion. Advances in Experimental Social Psychology, 19, 123–205. https://doi.org/10.1016/S0065-2601(08)60214-2

13. Items of the Scale