What makes a Web site credible?






Kath Straub, Ph.D., CUA, Chief Scientist of HFI, and Susan Weinschenk, Ph.D., Chief of Advanced Studies and Projects for HFI, ask the question - What makes a Web site credible?


 Web Credibility






What are the characteristics of a Web site that make a person decide the information at the site is credible? Recent research indicates that not all people make the decision of credibility using the same criteria. Domain experts (e.g., Doctors on a health site or Certified Financial Planners on a financial information site) focus on brand, company reputation, information sources, and internal fact-checking to evaluate the credibility of an information site. In contrast, consumers use characteristics such as look-and-feel and information design to evaluate credibility.




Recent research


Consumer watchdog/research groups have reported large scale surveys in which they asked internet users to report the criteria that they use to evaluate the credibility of Web sites [3,4]. Advocacy groups such as Consumer Web Watch (the Web watchdog arm of Consumers Union) and the Pew Internet and American Life Projects each report large scale surveys concluding that consumers report that they rely on the following types of information:

  1. Site owners/sponsors;
  2. Reported information sources/citations;
  3. Date of posting;
  4. Clearly distinguished content, editorial content and advertising copy.

In fact, both groups also report that, although consumers SAY that they use these factors to evaluate a site's authority and trustworthiness, they fail to actually do these things. Pew reports that only about one quarter of health information seekers actually check the source and timeliness of information every time they search for health information.

So what characteristics are they really using, not just reporting on? Fogg and colleagues conducted two major studies [1,2] exploring the characteristics of a Web site that influence consumers and domain experts separately. Participants were asked to explore/evaluate pairs of similar Web sites, rank the sites (within a given pair) as more or less credible than the other and then report why they selected that particular ranking.

A total of 2,864 participants completed the consumer study [1]. Participants rated site pairs from one of 10 randomly assigned content categories: E-commerce, Entertainment, Finance, Health, News, Non-profit, Opinion/Review, Search Engines, Sports or Travel. Each category contained 10 sites.

A total of 15 participants completed the expert study [2]. In this study, site categories were limited to Health and Finance. Again, participants ranked and commented on a random site pair. Participants were assigned to their domain expertise category.




What the studies found


Consumers who were not domain experts tended to use the same criteria even on different types of sites. The criteria used most often are (in order of frequency):

  • Design look
  • Information focus
  • Information design
  • Advertising
  • Company motive
  • Name and reputation
  • Information bias
  • Information accuracy
  • Writing tone
  • Information source

For the domain experts the most often used criteria were (in order of frequency):

  • Name
  • Information source
  • Company motive
  • Information focus
  • Advertising
  • Design look
  • Information bias
  • Information design
  • Writing tone
  • Information accuracy

Although these studies were conducted in the United States, similar findings have been found in other countries. In a study at the University of Heidelberg [5], consumers in a focus group confidently reported that they would look primarily to the information source to evaluate credibility of health information Web sites. However, in practice none of the participants explored the "About Us" sections of any of the sites that they visited. Further, participants could remember the name of the [Web site or] company or organization presenting task-critical information only about 20% of the time.

It seems that consumers use parameters of Web sites that they feel confident evaluating: Look and Information design. In short, attractive and easy-to-use Web sites are construed as being credible.




Possible explanations


In looking at why consumers use the factors they do there are several possible explanations.

Social Psychologists (and marketers) have known through research for quite some time that attractive people are responded to more positively than unattractive people - they receive more help, more job offers, higher pay and shorter prison sentences [6,7,8 and 9]. In the absence of other criteria for evaluation (or even in their presence), perhaps the same holds true for Web sites?

Or perhaps it is the famous "halo effect." A halo effect occurs when one positive characteristic of a person broadly influences the way that that person is viewed by others. Again, the positive characteristic is typically attractiveness. The halo of attractiveness broadly influences the perception of unrelated attributes:

  • Attractive children are viewed as being less naughty than their less attractive peers for the same behaviors [10],
  • Good looking people are automatically assigned favorable traits such as kindness, honesty and talent [11].

Apparently, attractive Web sites are attributed expertise and trustworthiness - the characteristics Fogg uses to define credibility - in the same way.




What is the impact?


In terms of design, we are reminded that effective design depends on knowing the audience: Site characteristics that influence credibility for domain experts are very different than those which influence consumers.

Look and usability are intimately correlated with Web credibility for general consumers. In the absence of expertise, consumers appeal to look and ease of use to evaluate a site's credibility. Not only are attractive, easy-to-use sites rated more credible than frustrating or chaotic ones, users explicitly acknowledge the importance of this characteristic in the evaluation process.






[1] Fogg, B.J., Soohoo, C., Danielsen, D., Marable, L., Stanford, J., & Tauber, E. (2002). How Do People Evaluate a Web Site's Credibility? Results from a Large Study. Stanford Persuasive Technology Lab, Stanford University.

[2] Stanford, J., Tauber, E., Fogg, B.J., Marable, L. (2002). Expert vs. Online Consumers: A Comparative Credibility Study of Health and Finance Web Sites.

[3] Princeton Survey Research Associates (2002). A Matter of Trust: What Users Want From Web Sites. Results of a National Survey of Internet Users for Consumer WebWatch.

[4] Vital Decisions: How Internet users decide what information to trust when they or their loved ones are sick (March 2002). Fox, S and Rainie, L. Pew, Internet and American Life Project Report: Washington, DC.

[5] Eysenbach, G., & Köhler, C. (2002). How do consumers search for and appraise health information on the world wide web? Qualitative study using focus groups, usability tests, and in-depth interviews British Medical Journal, 324, 573-577.

[6] Benson, P.L., Karabenic, S. A. and Lerner, R. M. (1976). Pretty Pleases: The effects of physical attractiveness on race, sex and receiving help. Journal of Experimental Social Psychology, 12, 409-415.

[7] Mack, D. & Rainey, D. (1990). Female applicants' grooming and personnel selection. Journal of Social Behavior and Personality, 5, 399-407.

[8] Hammermesch, D. and Biddle, J. E. (1994). Beauty and the labor market. The American Economic Review, 84, 1174-1194.

[9] Stewart, J. E. (1980). Defendant's attractiveness as a factor in the outcome of trials. Journal of Applied Social Psychology, 10, 217-238.

[10] Dion. K. K. (1972). Physical Attractiveness and evaluation of children's transgressions. Journal of Peronality and Social Psychology, 24, 207-213.

[11] Eagly, A.H., Ashmore, R. D., Makhijani, M. G. and Longo, L.C. (1991). What is beautiful is good, but...: A meta-analytic review of research of the physical attractiveness stereotype. Psychological Bulletin, 110, 109-128.