The Functional Triad Computers in Persuasive Roles


Based on my experience in teaching and speaking about captology, I’ve learned that the quickest way to help people grasp the subject is to introduce what I call the “functional triad.” This is a conceptual framework that illustrates the different roles that computing technology can play.

The functional triad is a framework that illustrates the three roles computing technology can play: tool, media, and social actor.

The functional triad overarches the various perspectives and theories on persuasion that have been developed since the days of Aristotle (see sidebar on page 24), while highlighting the potential of computing products to persuade and motivate. Having this framework makes it easier to design or study computers as persuasive technologies.

This brief chapter will provide an overview of the three key elements in the functional triad. The next three chapters will examine each element in more detail.

The Functional Triad Roles Computers Play

The functional triad is a framework for thinking about the roles that computing products play, from the perspective of the user. In its simplest form, the functional triad shows that interactive technologies can operate in three basic ways: as tools, as media, and as social actors (Figure 2.1). These three functions capture how people use or respond to virtually any computing product, from simple products like a portable electronic pedometer to sophisticated products such as TurboTax for the Web. Most computing products are a mix of these three functions, blending tool with social actor, or medium with tool, and so on.

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Figure 2.1: Computing technologies persuade in different ways, depending on their functional roles.

A Brief History of Persuasion Studies

The study of persuasion has a long history. In classical Greece, Aristotle was the leading thinker on the topic of rhetoric—the art of determining how to persuade in any given situation [1 ]In Aristotle’s day, rhetoricians were mainly concerned with giving public speeches that influenced their listeners. As part of their education, privileged Greek males studied how to use public speaking skills to change people’s moods, influence their opinions, or motivate them to action. The Greeks felt the art of speaking persuasively was key to maintaining a healthy democracy.

Today the formal study of persuasion continues to be advanced, primarily through research in social psychology, which began during the early part of the 1900s. Inspired largely by the U.S. government’s need to persuade citizens to support war efforts, social psychologists established ambitious research programs to determine what caused people to change their attitudes and behaviors. [2 ]Later, marketers and advertisers built on the insights gleaned from social psychology, systematically investigating how influence works and often applying their findings to help corporations prosper.

Despite the work of classical philosophers, modern psychologists, and contemporary marketers, there is no single definition of persuasion. Many theories and perspectives have come from the fields of rhetoric, psychology, marketing, and others. [3 ]All of these approaches contribute to our understanding of persuasion, but each has limitations. No single set of principles fully explains what motivates people and what causes them to adopt certain attitudes or to behave in certain ways.

Computers as Tools

One basic function of computers is to serve as tools. This is the first corner of the functional triad. In their role as tools, the goal of computing products is to make activities easier or more efficient to do (for example, math calculations or text manipulation), or to do things that would be virtually impossible without technology (such as tracking the location of a package you’ve sent or comparing a partial fingerprint with the thousands of criminal fingerprints on file).

When acting as tools, computers can influence and motivate people in specific ways. I’ll return to this topic after explaining the next two corners of the functional triad.

Computers as Media

Computers also function as media—a role that has grown in recent years as processing power has increased and networking has become common. There are two categories of computers as media: symbolic and sensory. Computers function as symbolic media when they use symbols to convey information (for example, text, graphics, charts, and icons). They function as sensory media when they provide sensory information—audio, video, and (rarely) even smell[4] and touch sensations. [5 ]Virtual reality and virtual environments fit into this category, as do a range of other computer simulations.

While both symbolic and sensory media can influence people, captology focuses primarily on computers functioning as sensory media—especially, as computer simulations—because in this role, computers have unique capabilities to provide interactive experiences that motivate and persuade. (In truth, the symbolic and the sensory are often intertwined in computer systems, making it difficult to draw a clear line between the two categories.)

Computers as Social Actors

The third corner of the functional triad depicts the role that computers play as social actors or living entities. When people use an interactive technology, they often respond to it as though it were a living being. Digital pets, such as Tamagotchis, a fad product of the mid-1990s, are a well-known example of this phenomenon. In some respects, Tamagotchi owners interacted with these digital life forms as though they actually were alive.

The popularity of Tamagotchis made it evident that people can respond to computing technologies as though they were living creatures. But there is plenty of other evidence that people respond to computers as social actors. You hear it in the language of computer users. Computers are put to “sleep,” they “wake up,” and sometimes they “die.” And people get emotionally involved with computer products. You’ve probably seen people get angry or swear at the computer when it doesn’t deliver as expected, or offer thanks when the computer comes through in a pinch.

The evidence goes beyond these little quirks in our language and emotions. In the 1990s, my colleagues and I performed controlled lab studies at Stanford University showing that people do indeed respond socially to computer technology. [6 ]In a series of experiments, we brought students into the lab and had them interact with computers on a specific task. Sometimes the computers gave advice for completing a part of the task, sometimes the computers praised people for doing work, and other times the computers needed favors and asked for compliance.

In all cases, the computers used simple dialogue boxes and never referred to themselves as “I” or as a living entity. Nevertheless, the students who participated in these experiments responded to the computers much like they would respond to another human being. Among other things, they treated their computers as teammates, they were motivated by praise from the computers, and they repaid favors the computers did for them. (I’ll present more details about these studies in Chapter 5.)

I should note that the participants in these experiments were computer savvy. In fact, a few of the studies included only graduate students in engineering, who know very well that computing devices are not living entities. Yet even these engineers responded in ways that indicated they were using the norms found in interactions between humans as they interacted with the computers. In summary, whether they mean to or not, people often treat computing products as though they were alive in some way.

[1 ]Specifically, in Book 1, Chapter 2, of Aristotle’s Rhetoric, rhetoric is defined as “the faculty of observing in any given case the available means of persuasion.”

[2 ]For an accounting of persuasion studies to support war efforts, see C. I. Hovland, I. L. Janis, and H. H. Kelley, Communication and Persuasion (New Haven, CT: Yale University Press, 1953). For more on the history of modern persuasion research, see W. J. McGuire, Attitudes and attitude change, in G. Lindzey and E. Aronson (eds.), The Handbook of Social Psychology (New York: Random House, 1985), vol. 2, pp. 238–241.

[3 ]M. E. Ford, Motivating Humans: Goals, Emotions, Personal Agency Beliefs (Newbury Park, CA: Sage, 1992).

[4]After the demise of the much-celebrated Digiscents, two companies are now vying to be the market leader in digital scent technologies: Savannah, Georgia–based Trisenx (see and Plano, Texas–based Aroma Jet (see

[5 ]One company that is innovating computer systems that leverage the sense of touch is Immersion Corporation in San Jose, California (see

[6 ]To read about multiple experiments supporting the idea that people respond socially to computers, see the following:

a. B. Reeves and C. Nass, [The Media Equation: How People Treat Computers, Television, and New Media Like Real People and Places ](New York: Cambridge University Press, 1996).

b. B. J. Fogg, Charismatic Computers: Creating More Likable and Persuasive Interactive Technologies by Leveraging Principles from Social Psychology, doctoral dissertation, Stanford University, 1997.

Applying the Functional Triad to Captology

Understanding the functional triad is essential to leveraging or analyzing the persuasive power of computers. Persuasion strategies will differ depending on whether a computing technology is functioning as a tool, a medium, or a social actor. Each corner of the functional triad comes with its own set of persuasion techniques, which will be explored in the next three chapters.

In functioning as tools, computers can influence people in a number of ways. For example, they can make a target behavior easier to perform, lead users through a process, or perform calculations or measurements that motivate. These and other approaches will be explored in Chapter 3.

When functioning as sensory media, computing technology can persuade people by providing compelling experiences through simulations. These computer simulations persuade by enabling people to explore cause-and-effect relationships, by providing vicarious experiences that motivate, or by helping people rehearse a behavior. These persuasive approaches are explored in Chapter 4.

Persuasion strategies differ depending on the role being played by the computer: tool, medium, or social actor.

Finally, when computing products adopt the role of social actor, they persuade people by applying the same persuasion principles that humans use to influence others; as social actors, computers can persuade people to change their attitudes or behaviors by rewarding them with positive feedback, modeling a target behavior or attitude, or providing social support. Chapter 5 discusses computers as persuasive social actors in more detail.

Research and Design Applications

For those with an interest in researching or designing persuasive technologies, the functional triad provides a framework for sorting out the elements in the overall user experience of a product. For researchers, identifying which elements of the product are acting as a tool, medium, social actor, or some combination of the three roles, makes it easier to understand the nature of the product’s persuasive power. In my experience, this simple step often brings clarity to a research or analysis project and provides a basis for further exploration.

The functional triad also can help designers of persuasive technologies. When exploring ideas for a new product, designers can ask themselves how the product might persuade as a tool, medium, social actor, or through a combination of roles. Answering these questions in depth should produce many ideas about design options for Web sites, desktop applications, or mobile devices.

As an example, consider the task of designing a Web site to motivate people to get more physically fit. This online system could act as a persuasive tool, medium, social actor, or some combination of the three. As a designer steps through the three corners of the functional triad, different strategies for motivation and influence will become apparent.

As a tool, the system could lead a person through a step-by-step process of identifying personal barriers to eating better and exercising regularly. It could then take into account the person’s preferences, family situation, and work constraints in suggesting realistic ways to overcome those barriers to better health. Furthermore, it could track and visually display how well the person is progressing toward fitness goals.

As a medium, the system could allow the person to rehearse in a virtual context healthier eating behaviors, such as choosing to eat only half of what’s served while dining out and packaging up the other half to go before starting to eat. Also functioning as a medium, the system could allow the person to experiment with different diet and exercise routines to view the probable effect they would have on losing weight and increasing cardiovascular fitness over weeks and months, making more apparent key cause-and-effect relationships related to health.

Finally, as a social actor, the online system could be designed to take on the role of a knowledgeable and supportive health counselor. In this role, the system could use language to instruct, encourage, and praise users as they progress in their efforts to become healthier.

As this example suggests, the functional triad has practical applications for designers of persuasive technology products and for those who want to understand how computers can persuade. In the next three chapters, each corner of the functional triad will be explored in depth.

For updates on the topics presented in this chapter, visit

Persuasive Technology(c) Using Computers to Change What We Think and Do
Persuasive Technology: Using Computers to Change What We Think and Do (Interactive Technologies)
ISBN: 1558606432
EAN: 2147483647
Year: 2005
Pages: 103
Authors: B.J. Fogg © 2008-2020.
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