KOL, influencer and purchase intention survey (Ohanian)

KOLs, KOCs and livestream selling are very popular topics in marketing theses. This template uses the source credibility scale of Ohanian (1990) to evaluate the endorser, linked to brand attitude and willingness to buy following Dodds, Monroe and Grewal (1991).

Research model

Suggested model, to be justified from your literature review: the endorser's attractiveness, trustworthiness and expertise (Ohanian, 1990) increase positive brand attitude (Spears and Singh, 2004), and brand attitude increases willingness to buy.

• Attractiveness → Attitude toward the Brand (positive)
• Trustworthiness → Attitude toward the Brand (positive)
• Expertise → Attitude toward the Brand (positive)
• Attitude toward the Brand → Willingness to Buy (positive)

Questionnaire items

Original English wording. Answered on a 5-point Likert scale (1 = Strongly disagree … 5 = Strongly agree) unless the scale page says otherwise; (R) marks a reverse-coded item.

Attractiveness (ATT) · Source credibility scale

Code	Item
ATT1	Unattractive – Attractive
ATT2	Not classy – Classy
ATT3	Ugly – Beautiful
ATT4	Plain – Elegant
ATT5	Not sexy – Sexy

Source: Ohanian (1990). See Source credibility scale.

Trustworthiness (TRU) · Source credibility scale

Code	Item
TRU1	Not dependable – Dependable
TRU2	Dishonest – Honest
TRU3	Unreliable – Reliable
TRU4	Insincere – Sincere
TRU5	Untrustworthy – Trustworthy

Source: Ohanian (1990). See Source credibility scale.

Expertise (EXP) · Source credibility scale

Code	Item
EXP1	Not an expert – Expert
EXP2	Inexperienced – Experienced
EXP3	Unknowledgeable – Knowledgeable
EXP4	Unqualified – Qualified
EXP5	Unskilled – Skilled

Source: Ohanian (1990). See Source credibility scale.

Attitude toward the Brand (AB) · Attitude toward the ad and brand scales (Aad, Ab)

Code	Item
AB1	Unappealing – Appealing
AB2	Bad – Good
AB3	Unpleasant – Pleasant
AB4	Unfavorable – Favorable
AB5	Unlikable – Likable

Source: Spears & Singh (2004). See Attitude toward the ad and brand scales (Aad, Ab).

Willingness to Buy (WTB) · Willingness to buy scale

Code	Item
WTB1	The likelihood of purchasing this product is (very high … very low).
WTB2	If I were going to buy this product, I would consider buying this model at the price shown.
WTB3	At the price shown, I would consider buying the product.
WTB4	The probability that I would consider buying the product is (very high … very low).
WTB5	My willingness to buy the product is (very high … very low).

Source: Dodds, Monroe & Grewal (1991). See Willingness to buy scale.

Tips

• Choose one endorser and one specific product, show respondents a photo or clip, and ask a screening question about whether they know the person.
• The Ohanian scale and the brand attitude scale are bipolar adjective pairs, not agreement statements; this page and the Survey Kit present them as 5-point semantic differential scales.
• If the literature supports it, add a direct path from trustworthiness to willingness to buy and test the mediating role of attitude.
• Attractiveness and trustworthiness sometimes cross-load in Vietnamese samples; check discriminant validity with HTMT.

Work out the minimum sample size for this model; once the data are in, clean the responses and run the survey data analysis for your results chapter.

Studies that used this model

• Khuong An, Thuy An Ngo, Tu Tran and Thy Nguyen (2024). Investigating the influence of social media influencer credibility on beauty product purchase behaviors: a case study from Vietnam. Innovative Marketing, 20(3), 261–276. Sample: 269 consumers; three Ohanian dimensions → purchase intention → cosmetics buying behavior. Reliability: α 0.768-0.859; CR 0.833-0.912 (Table 1).
• Le, Vu and Le (2024). Source credibility of beauty vloggers and consumer purchases of vegan cosmetics: The mediating role of cognitive and affective attitude. Innovative Marketing, 20(3), 14–27. Sample: 382 YouTube viewers; Ohanian (1990) → cognitive and affective attitude → purchase intention. Reliability: α 0.804-0.904; CR 0.884-0.932 (Table 3).
• Tran, Ta, Luu, Ta, Vo and Pham (2025). Effect of KOLs' persuasiveness on impulsive buying behaviors: live streaming commerce. Cogent Business & Management, 12(1), 2476709. Sample: 360 Gen Z respondents; KOL attractiveness, trustworthiness, expertise → persuasiveness → impulse buying. Reliability: .

Collecting responses

If your own network cannot reach the target respondents, you can pay for verified responses through Genius Data (referral link, we may earn a commission), paying only for approved responses.