Overview

Are computers credible? That s a question I like to ask students in my Stanford classes. It invariably generates a lively debate.

There s no easy answer, but the question is an important one. When it comes to believing information sources including computers credibility matters. Credible sources have the ability to change opinions, attitudes, and behaviors, to motivate and persuade. In contrast, when credibility is low, the potential to influence also is low. ^{[1 ]}

Throughout most of the brief history of computing, people have held computers in high esteem ^[2] a view that is reflected in popular culture. Over the past several decades, computers often have been portrayed as infallible sidekicks in the service of humanity, from Robby the Robot in Forbidden Planet, the 1956 movie classic, to B-9, the robot in the 1960s television program Lost in Space, to R2-D2 in Star Wars. ^{[3 ]}

In the consumer realm, computer-based information and services have been marketed as better, more reliable, and more credible sources than humans. Marketers assured the buying public that if a computer said it or produced it, then it s believable.

Due in part to the emergence of the Internet and the proliferation of less than- credible Web sites, the cultural view of computers as highly credible sources has been seriously challenged. (Web credibility, which deserves special attention, is the subject of Chapter 7.) As consumers become more skeptical, it s important for designers of persuasive technology to understand the components of credibility, the contexts in which credibility matters,...