web credibility variables public

What Variables Affect Web Credibility? Slide #1

Contact: BJ Fogg ([email protected])www.webcredibility.org

What Variables Affect Web Credibility?

A Report of Ongoing Research from Stanford’s Persuasive Technology Lab

BJ Fogg ([email protected])

First presented at CSLI’s Industrial Affiliate Conference

Stanford University, November 11, 1999



Overview

Level 1 A First Look at Credibilitydefinitions, basic issues

Level 2 Four Types of Credibilitydifferent kinds of credibility

Level 3 Web Site Variablesweb elements and a framework

Level 4 Variables Outside the Webindividuals, goals, and contexts

Level 5 Three Moving Targetspeople, experience levels, and technology

Plus two studies



Level 1 A First Look at Credibility






Plus two studies



Why does Web credibility matter?

Web sites with optimal levels of

credibility

Creators

What to believe on the web

(aka “information quality”)

Consumers

A key factor in Web-based persuasion

PT Lab

Answer #1



Why does Web credibility matter?

Few have studied this

(publicly)

Web has least credible info of

any medium

Web has most credible info of

any medium

Web standards are taking shape

now

The Web is not going away

any time soon

Big money is at stake

Web presence is vital for many

companies

Explosion of Web-based info

& services

Web users are vulnerable

Answer #2



What is “credibility”?

• Believability

or

• A perception based on two factors* . . .

trustworthiness expertise

honest

truthfulunbiased

powerful

intelligent

knowledgeable

experienced

good

*Some studies have shown three or more factors

+



Highly credible web sites have. . .

• High levels of perceived trustworthiness and expertise

perceived

trustworthinessperceived

expertiseperceived

credibility+



One factor can damage credibility

perceived lack of

trustworthinessperceived

expertiseperceived lack of

credibility+

perceived

trustworthinessperceived lack of

expertiseperceived lack of

credibility+



Some semantic issues

“Credibility” and “Trust”• Similar terms but not the same construct

Phrases that refer to credibility• “trust the information”

• “accept the advice”

• “believe the output”



Expertise & Trustworthiness

In these examples, what elements convey expertise? What elements convey trustworthiness?



Level 2 Four Types of Credibility






Plus two studies



Four Types of Credibility

1. Presumed Credibility

2. Reputed Credibility

3. Surface Credibility

4. Experienced Credibility

• It’s helpful to distinguish different types of credibility.• But you won’t find these distinctions in the psychology

literature.




• We believe because of general assumptions we hold.




• We believe because of general assumptions we hold.

• Examples* . . .

Increases credibility Decreases credibility

Domain name has “.org”

Lots of hits on web counter

Info on the site is constantly updated

Site has AOL domain name

Very few hits on web counter

Info on the site is rarely updated

*These are working hypotheses. To date, we’ve studied only some of these variables.



2. Reputed credibility

• We believe because of a reference from a third party.



2. Reputed credibility

• We believe because of a reference from a third party.

• Examples* . . .


Your medical doctor referred you to this Web site.

The site won an award.

An authoritative Web site linked to this site.

Your friend said the site was horrible.

The newspaper said the site was down for three days.

A political group you don’t like endorses the site.




3. Surface credibility

• We believe because of what we find on simple inspection.



3. Surface credibility

• We believe because of what we find on simple inspection.

• Examples* . . .


Site looks professional.

Site is from an organization you recognize.

You see that articles have citations.

Site looks confusing.

The organization has no presence outside the Web.

The site uses many animated features.




4. Experienced credibility

• We believe because of past experience with site.



4. Experienced credibility

• We believe because of past experience with site.

• Examples* . . .


You get a quick response to a customer service question.

You can navigate the site easily.

You’ve found the content to be fair and balanced.

The site has a broken link.

The site takes a long time to download each page.

You’ve seen factual errors on the site.




Why this framework is helpful

• Provides a set of terms for discussion

• Enhances both research & design• Asking better questions• Seeing more possibilities

PresumedCredibility

ReputedCredibility

SurfaceCredibility

ExperiencedCredibility

Trustworthiness

Expertise



Why this framework is helpful

• Provides a set of terms for discussion

• Enhances both research & design• Asking better questions• Seeing more possibilities

PresumedCredibility

ReputedCredibility

SurfaceCredibility


Trustworthiness

Expertise




• Presumed• Reputed• Surface• Experienced

Can you identify the different types of credibility in these examples?



Level 3 Web Site Variables






Plus two studies



Level 3 Web Site Variables

• How to contain the many elements of a Web site?

• We’ve created some frameworks » I’ll talk about one.» See www.webcredibility.org for others.



Framework for Web Site Elements

Web Site Provider• Person or organization that offers the site

» e.g., IBM, Kodak, Amazon

Web Site Content• Information • Functionality

Web site Design • Aesthetic design• Information design• Technical design



Web Credibility Grid

Web SiteProvider

Web SiteContent

Web SiteDesign

PresumedCredibility

ReputedCredibility

SurfaceCredibility


•information•functionality

•aesthetic•information•technical




Web SiteProvider

Web SiteContent

Web SiteDesign

PresumedCredibility

ReputedCredibility

SurfaceCredibility


The provider is a nonprofit organization.

The site was created by an outside design firm.

The site has ads from reputable companies.

Users are familiar with the provider outside of the Web context.

The provider is recognized as an expert by others.

The site’s content has always been accurate and unbiased.

The site is easy to navigate.

The site appears to have lots of relevant information.

The content has been approved by an outside agency.

The site won an award for technical achievement.

The site has a pleasing visual design.

Users with questions receive quick and helpful answers.

Examples of elements that increase credibility*







Web SiteProvider

Web SiteContent

Web SiteDesign

PresumedCredibility

ReputedCredibility

SurfaceCredibility


The site tries to recruit advertisers but has none so far.

The site has no security protocols for transactions.

The site shows only a few hits on their web counter.

The site’s URL does not match the provider’s name.

The provider was sued for patent infringement and lost.

The site has typographical errors.

The site has links to pages that no longer exist.

The site seems to have more ads than information.

The content got bad reviews from an outside agency.

The site is reported to have copied the design of another site.

The text font is either too large or small to read comfortably.

The site doesn’t give contact information anywhere.

Examples of elements that decrease credibility*






Small Survey on Web Credibility

Pilot study on 45 variables• Questionnaire, n = 25, with Nina Kim• Purpose: To select variables for experiment

Sample question:

The Web site lists an author for each article.

-3 -2 -1 0 +1+2 +3

much much

less more

credible credible



Survey results were interesting*

mo

re c

red

ible

less credib

le

Was referred to you by a good friend

Contains a link to a site you trust

Contains an ad for IBM

Contains many spelling and grammatical errors

Was created with PageMill or FrontPage software

Charges a monthly access fee

Contains broken links

Contains misleading ads

Makes it difficult to distinguish ads from content

Contains a typographical error

Has “.com” in the domain

Contains animation

Has “.org” in the domain

Lists an author for each article

Lists a physical address for the page sponsor

Is easy to navigate

Provides quick response to a customer service question

Presents information that may help its competitors

Represents a company or organization you recognize

*The sample size in this survey was too small to draw firm conclusions



Lab Experiment on Web Credibility

Selected two Web credibility variables for Nina Kim’s thesis experiment

• ads

• typos



Web credibility research

Experimental Design

Controlled lab study• 2X2 mixed design, n = 38

• Health information taken from Web

• Independent variables– typos or no typos– ads or no ads

• Dependent variables– questionnaire after viewing




Sample Stimuli

No typos Typos

vs




Sample Stimuli

No Ad Ad

vs




Sample Stimuli

Other sample pages




What did the data show?

• Typos decreased the credibility of page.

• Ads increased the credibility of page.

• Both effects are stronger for vital info than for less vital info.



Level 4 Variables Outside the Web






Plus two studies



Level 4: Variables Outside the Web

Individual variables– user differences (age, experience, personality, etc.)

Goal variablesFor example,

– information seeking on health– surveillance of current events– passing time, entertainment

Context variables– setting– time factors– technology factors



Level 5 Three Moving Targets






Plus two studies



Level 5: Three Moving Targets

Three things are changing . . .1. People

– Web user base will become more diversified.

2. Experience levels– Web users will become more savvy.

3. Technology– Web technology and uses will change.

These moving targets mean . . .• Perceptions of Web credibility will shift over time.• We need an ongoing effort to understand Web credibility.



Ongoing research efforts at PTL

Research on web credibility perceptions• www.webresearch.org

Web credibility experiments• Online and in the lab

Gathering other work on Web credibility• Pointers at www.webcredibility.org



In Review






Plus two studies



What Variables Affect Web Credibility?

A Report of Ongoing Research from Stanford’s Persuasive Technology Lab

BJ Fogg ([email protected])

First presented at CSLI’s Industrial Affiliate Conference

Stanford University, November 11, 1999

web credibility variables public

Education

web credibility matter

experienced credibility

credibility definitions

presumed credibility

reputed credibility

surface credibility

types of credibility

different types of credibility