What Makes Web Sites Credible

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What Makes Web Sites Credible?

• A Report on a Large Quantitative Study

B.J. Fogg, Jonathan Marshall, Othman Laraki, Alex
Osipovich, Chris Varma, Nicholas Fang, Jyoti
Paul, Akshay Rengnekar, John Shon, Preeti Swani,
Marissa Trienen Stanford Persuasive
Technology Lab www.captology.org
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Do you believe what you seeon the Web today?
No . . .
. . . but Yes
Our Research Question What elements affect the
credibility of Web sites? No large-scale study
performed on this topic.
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What is credibility anyway?

• Believability
• or
• A perception based on two factors . . .

truthful
experienced
unbiased
intelligent

trustworthiness
expertise
powerful
good
honest
knowledgeable
Some studies have shown three or more factors
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We could guess that . . .

• Highly credible sites would have high levels of
  perceived trustworthiness expertise
• But we wanted data.
• And lots of it. So we ran a large-scale survey.

perceived trustworthiness
perceived expertise
perceived credibility
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Our Research Method

• Online survey
• Surveys have weaknesses but good for . . .
• Getting lots of data
• Over 1400 participants, from U.S. and Finland in
  12/99
• 10 donation to charity for participation
• Setting baseline values for future research
• Question design
• We identified over 300 items affecting web
  credibility.
• Three pilot tests helped narrow list to 51 items.

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Excerpt from online study
Respondents did not view a particular Web site
for this study. Instead, they answered these
questions by drawing on their cumulative
experience using the Web. (ave. 3.7 years
13.9 hrs/week)
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Who participated?

• Median age 33 years
• 44 female
• 42 U.S., 58 Finland
• Education level some university
• Income mean 31,459
• Years on net 3.7 years
• Average time per week on net 13.9 hours

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Results Overview

• 51 items clustered into 7 factors

Real-World Feel
Ease of Use
Increases Credibility
Expertise
Trustworthiness
Tailoring
Commercial Implications
Decreases Credibility
Amateurism
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Real-World Feel Factor
10
Ease of Use Factor
11
Expertise Factor
12
Trustworthiness Factor
13
Tailoring Factor
14
Commercial Implications Factor
15
Amateurism Factor
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What we like about this study

• Online research method
• Asked questions in random order
• Gathered lots of data quickly
• Included participants from around the world
• Donated to charity groups
• Results
• Baseline for 51 Web site elements
• Surprisingly important ease of use, simple
  details
• Ability to take the next steps . . .

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Next steps in Web credibility

• Perform controlled experiments online
• Focus on a few factors at a time
• Random assignment to condition
• Between-groups experimental design

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What Makes Web Sites Credible?

• A Report on a Large Quantitative Study

B.J. Fogg, Jonathan Marshall, Othman Laraki, Alex
Osipovich, Chris Varma, Nicholas Fang, Jyoti
Paul, Akshay Rengnekar, John Shon, Preeti Swani,
Marissa Trienen Stanford Persuasive
Technology Lab www.captology.org